EP4747610A1

EP4747610A1 - Antibody concentration measurement, titer module, and liquid storage module for cell analysis system

Info

Publication number: EP4747610A1
Application number: EP24752310.3A
Authority: EP
Inventors: Jordan BILLER; Matthew Freeman; Aaron GUSTAFSON; Todd Halvorson; Julie Lutti; Timothy Reed
Original assignee: Beckman Coulter Inc
Current assignee: Beckman Coulter Inc
Priority date: 2023-07-21
Filing date: 2024-07-19
Publication date: 2026-05-27
Also published as: WO2025024321A1; CN121399448A; JP2026525271A

Abstract

A system for measuring a concentration of an antibody in a sample includes a polarizer holder retaining first and second detection polarizers. The first detection polarizer restricting passage of light fluoresced from within a container to a first direction. The second detection polarizer restricting passage of light fluoresced from within the container to a second direction. The second direction is perpendicular to the first direction. The system includes a detector for measuring the light fluoresced in the first direction and the light fluoresced in the second direction. The system rotates the polarizer holder about an axis of rotation in alternating directions causing alternate placement of the first and second detection polarizers in an optical path of the light fluoresced from within the container.

Description

ANTIBODY CONCENTRATION MEASUREMENT, TITER MODULE, AND LIQUID STORAGE MODULE FOR CELL ANALYSIS SYSTEM

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application is being filed on July 19, 2024, as a PCT International application and claims the benefit of and priority to U.S. Application No. 63/514,929, filed on July 21, 2024, entitled ANTIBODY CONCENTRATION MEASUREMENT, TITER MODULE, AND LIQUID STORAGE MODULE FOR CELL ANALYSIS SYSTEM, the disclosure of which is hereby incorporated by reference in its entirety.

BACKGROUND

[0002] An antibody is a large. Y-shaped protein used by the immune system to identify and neutralize foreign objects such as pathogenic bacteria and viruses. The antibody recognizes a unique molecule of the pathogen, called an antigen. Each tip of the Y-shaped antibody contains a paratope that matches an epitope on the antigen, allowing the antibody to bind with the antigen. Using this binding mechanism, an antibody can tag a microbe or an infected cell for attack by other parts of the immune system, or can neutralize the microbe or the infected cell directly. Immunoglobulin G (IgG) is the most common type of antibody found in blood circulation. A concentration of an antibody in a cell sample can be measured by fluorescence polarization.

SUMMARY

[0003] In general terms, the present disclosure relates to measuring a concentration of an antibody in a cell sample by fluorescence polarization. In one possible configuration, a measurement cycle is performed to reduce errors that can result from signal intensity variations and noise during fluorescence polarization. Various aspects are described in this disclosure, which include, but are not limited to, the following aspects.

[0004] One aspect relates to a method of fluorescence polarization for measuring a concentration of an antibody in a sample, the method comprising: performing a measurement cycle measuring a first set of sampling phases of light fluoresced in a first direction and a second set of sampling phases of the light fluoresced in a second direction, at least one sampling phase of the light fluoresced in the second direction occurring between sampling phases of the light fluoresced in the first direction; calculating a first value of the first set of sampling phases; calculating a second value of the second set of sampling phases; and determining the concentration of the antibody based on a function of the first and second values.

[0005] Another aspect relates to a fluorescence polarization system for measuring a concentration of an antibody in a sample, the system comprising: a light source; a first polarizing filter causing light emitted from the light source to be polarized in a first direction; a container holding the sample mixed with a fluorescence polarization assay, the container receiving the light polarized in the first direction; movable second and third polarizing filters, the second polarizing filter restricting passage of light fluoresced from within the container to the first direction, and the third polarizing filter restricting the passage of the light fluoresced from within the container to a second direction, the second being substantially direction being perpendicular to the first direction; a detector for measuring the light fluoresced in the first direction and the light fluoresced in the second direction; and a processing circuitry having a memory for storing instructions which, when executed by the processing circuitry, cause the processing circuitry to: perform a measurement cycle measuring a first set of sampling phases of the light fluoresced in the first direction and a second set of sampling phases of the light fluoresced in the second direction, at least one sampling phase of the light fluoresced in the second direction occurring between sampling phases of the light fluoresced in the first direction; calculate a first value of the first set of sampling phases; calculate a second value of the second set of sampling phases; and determine the concentration of the antibody based on a function of the first and second values. [0006] Another aspect relates to a method of fluorescence polarization for measuring a concentration of an antibody in a cell sample, the method comprising: performing a measurement cycle of light fluoresced from within the cell sample mixed with a fluorescence polarization assay, the measurement cycle including the following order of measurements: (1) measuring a first sampling phase of light fluoresced in a first direction before a midpoint of the measurement cycle; (2) measuring a second sampling phase of light fluoresced in a second direction before the midpoint of the measurement cycle, the second direction being perpendicular to the first direction; (3) measuring a third sampling phase of the light fluoresced in the second direction after the midpoint of the measurement cycle; and (4) measuring a fourth sampling phase of the light fluoresced in the first direction after the midpoint of the measurement cycle; calculating a first average of the first and fourth sampling phases; calculating a second average of the second and third sampling phases; and determining the concentration of the antibody based on a function of the first and second averages.

[0007] Another aspect relates to a fluorescence polarization system for measuring a concentration of antibody protein in a cell sample, the system comprising: a processing circuitry having a memory for storing instructions which, when executed by the processing circuitry, cause the processing circuitry to: perform a measurement cycle of light fluoresced from the cell sample, the measurement cycle including the following order of measurements: (1) measuring a first sampling phase of light fluoresced in a first direction before a midpoint of the measurement cycle; (2) measuring a second sampling phase of light fluoresced in a second direction before the midpoint of the measurement cycle, the second direction being perpendicular to the first direction; (3) measuring a third sampling phase of the light fluoresced in the second direction after the midpoint of the measurement cycle; and (4) measuring a fourth sampling phase of the light fluoresced in the first direction after the midpoint of the measurement cycle; calculate a first average of the first and fourth sampling phases; calculate a second average of the second and third sampling phases; and determine the concentration of the antibody based on a function of the first and second averages.

[0008] Another aspect relates to a fluorescence polarization system for measuring a concentration of Immunoglobulin G (IgG) in a sample, the system comprising: a processing circuitry having a memory for storing instructions which, when executed by the processing circuitry, cause the processing circuitry to: perform a measurement cycle measuring a first set of sampling phases of light fluoresced in a first direction and a second set of sampling phases of the light fluoresced in a second direction, the second direction being substantially perpendicular to the first direction, at least one sampling phase of the light fluoresced in the second direction occurring between sampling phases of the light fluoresced in the first direction, each sampling phase in the first and second sets of sampling phases including voltage measurements of the light from a plurality of light pulses emitted by a light source; obtain a plurality of voltage measurements from each light pulse, wherein the plurality of voltage measurements from each light pulse includes a first set of voltage measurements when the light source is turned on, and a second set of voltage measurements when the light source is turned off; calculate an average of the first set of voltage measurements; calculate an average of the second set of voltage measurements; determine a light pulse differential value for each light pulse by subtracting the average of the second set of voltage measurements from the average of the first set of voltage measurements; determine a voltage value for each sampling phase by calculating an average of the light pulse differential values of the plurality of light pulses in each sampling phase; determine a first polarization value for the first set of sampling phases by calculating an average of the voltage values in the first set of sampling phases; determine a second polarization value for the second set of sampling phases by calculating an average of the voltage values for the second set of sampling phases; and determine a concentration value of the IgG by subtracting the second polarization value from the first polarization value, and dividing by a sum of the first and second polarization values.

[0009] Another aspect relates to a cell analysis system for measuring a concentration of an antibody in a sample, the system comprising: a light source; an excitation polarizer polarizing light emitted from the light source in a first direction; a container configured to receive the light polarized in the first direction; a polarizer holder retaining first and second detection polarizers, the first detection polarizer restricting passage of light fluoresced from within the container to the first direction, and the second detection polarizer restricting the passage of the light fluoresced from within the container to a second direction, the second direction being perpendicular to the first direction; a detector for measuring the light fluoresced in the first direction and the light fluoresced in the second direction; and processing circuitry having a memory for storing instructions which, when executed by the processing circuitry, cause the processing circuitry to: rotate the polarizer holder about an axis of rotation in alternating directions causing alternate placement of the first and second detection polarizers in an optical path of the light fluoresced from within the container.

[0010] Another aspect relates to a polarizer holder for a cell analysis system, the polarizer holder comprising: a first side surface; a second side surface perpendicular to the first side surface; a curved surface connecting the first and second side surfaces; a first detection polarizer coupled on the first side surface, the first detection polarizer restricting passage of light fluoresced to a first direction; and a second detection polarizer coupled on the second side surface, the second detection polarizer restricting passage of light fluoresced to a second direction; the polarizer holder being configured to rotate about an axis of rotation causing alternate placement of the first and second detection polarizers in an optical path of the light. [0011] Another aspect relates to a method of fluorescence polarization for measuring a concentration of an antibody in a sample, the method comprising: positioning a polarizer holder in a first position such that a first detection polarizer is placed in an optical path of light fluoresced from within a container holding a sample of antibody mixed with a fluorescence polarization assay; detecting the light fluoresced from within the container after the light passes through the first detection polarizer, the first detection polarizer restricting passage of the light fluoresced from within the container to a first direction; rotating the polarizer holder about an axis of rotation to position the polarizer holder in a second position such that a second detection polarizer is placed in the optical path of the light fluoresced from within the container, the second detection polarizer restricting passage of the light fluoresced from within the container to a second direction; and detecting the light fluoresced from within the container after the light passes through the second detection polarizer.

[0012] Another aspect relates to a module for a cell analysis system, the module comprising: a base having an interior volume holding an internal reservoir; a primary’ lid connected to the base, the primary lid including a port providing access to the internal reservoir; a secondary lid attached to the primary lid, the secondary lid configured to seal the port on the primary’ lid; a motor attached to the secondary’ lid; and a processing circuitry having a memory for storing instructions which, when executed by the processing circuitry, cause the processing circuitry to: operate the motor to open the secondary lid allowing a probe to be inserted through the port on the primary’ lid to reach a bottom of the internal reservoir; and operate the motor to close the secondary' lid to seal the port on the primary lid when the probe is removed.

[0013] A variety of additional aspects will be set forth in the description that follows. The aspects can relate to individual features and to combination of features. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the broad inventive concepts upon which the embodiments disclosed herein are based.

DESCRIPTION OF THE FIGURES

[0014] The following drawing figures, which form a part of this application, are illustrative of the described technology’ and are not meant to limit the scope of the disclosure in any manner. [0015] FIG. 1 is an isometric view of an example of a cell analysis system that analyzes cell health of a plurality of cell samples.

[0016] FIG. 2 is another isometric view of the cell analysis system of FIG. 1 having atop cover removed from a housing of the cell analysis system.

[0017] FIG. 3 is a top view of a work platform supported inside the housing of the cell analysis system of FIG. 1.

[0018] FIG. 4 schematically illustrates an example of a titer module supported on the work platform of FIG. 3.

[0019] FIG. 5 graphically illustrates an example of a plot showing detected light intensity drift in the titer module of FIG. 4 causing an error in calculating a concentration of antibody.

[0020] FIG. 6 graphically illustrates a plot showing simulated fluorescent polarization measurement errors that result from a measurement sequence shown in the plot of FIG. 5.

[0021] FIG. 7 schematically illustrates an example of a method of measuring a concentration of antibody in a cell sample that can be performed by the titer module of FIG. 4.

[0022] FIG. 8 schematically illustrates an example of a method of performing a measurement cycle in an operation of the method of FIG. 7.

[0023] FIG. 9 schematically illustrates an example of a measurement cycle performed in accordance with the method of FIG. 8.

[0024] FIG. 10 graphically illustrates an example of a plot showing how the method of FIG. 7 reduces errors in calculating a concentration of antibody in a sample of cells.

[0025] FIG. 11 graphically illustrates a plot showing reduced fluorescent polarization measurement errors that result from the measurement cycle of FIGS. 8-10.

[0026] FIG. 12 schematically illustrates a method of measuring a sampling phase performed in the measurement cycle of FIGS. 8-10.

[0027] FIG. 13 schematically illustrates an example of a controller of the cell analysis system of FIG. 1 that can be used to implement aspects of the titer module of FIG. 4.

[0028] FIG. 14 is an isometric view of an example of a titer module that can be used in the cell analysis system of FIG. 1. [0029] FIG. 15 is an isometric view of the titer module of FIG. 14 with a portion of a housing removed exposing internal components of the titer module.

[0030] FIG. 16 is an isometric cross-sectional view taken along a horizonal axis of the titer module of FIG. 14.

[0031] FIG. 17 is an isometric view of the titer module of FIG. 14 with internal covers removed exposing optical components of the titer module.

[0032] FIG. 18 is a right side view of the optical components of the titer module of FIG 14

[0033] FIG. 19 is a left side view of the optical components of the titer module of FIG. 14.

[0034] FIG. 20 is an isometric cross-sectional view taken along a vertical axis of the titer module of FIG. 14.

[0035] FIG. 21 is a cross-sectional right side view of the titer module of FIG. 14.

[0036] FIG. 22 is a cross-sectional left side view of the titer module of FIG. 14.

[0037] FIG. 23 is an isometric view of a polarizer holder, an optics plate, and a detector of the titer module of FIG. 14.

[0038] FIG. 24 is another isometric view of the polarizer holder, the optics plate, and the detector of the titer module of FIG. 14.

[0039] FIG. 25 is an exploded view of the polarizer holder of the titer module of FIG. 14.

[0040] FIG. 26 is an exploded view of the polarizer holder of the titer module of FIG. 14.

[0041] FIG. 27 is a top view of the polarizer holder of the titer module of FIG. 14.

[0042] FIG. 28 is an isometric view of the optics plate and a motor of the titer module of FIG. 14 with the polarizer holder removed therefrom.

[0043] FIG. 29 is a top view of the optics plate of FIG. 26.

[0044] FIG. 30 is an isometric view of a liquid storage module of the cell analysis system of FIG. 1.

[0045] FIG. 31 is another isometric view of the liquid storage module of FIG. 30 showing a lid of the liquid storage module in an opened position.

[0046] FIG. 32 is another isometric view of the liquid storage module of FIG. 30 showing an internal reservoir partially removed from an interior the liquid storage module. [0047] FIG. 33 is another isometric view of the liquid storage module of FIG. 30 showing an automated lid of the liquid storage module in an opened position.

[0048] FIG. 34 is another isometric view of the liquid storage module of FIG. 30 showing the lid of the liquid storage module in the opened position.

[0049] FIG. 35 is an isometric view of a secondary⁷ lid of the liquid storage module of FIG. 30.

[0050] FIG. 36 is a front view of the secondary lid of FIG. 35.

[0051] FIG. 37 is a side view of the secondary lid of FIG. 35.

[0052] FIG. 38 is a bottom view of the secondary⁷ lid of FIG. 35.

[0053] FIG. 39 is an isometric view inside the cell analysis system of FIG. 1 showing a dispensing system positioning a probe near the liquid storage module of FIG. 30.

[0054] FIG. 40 is an isometric view inside the cell analysis system of FIG. 1 showing the dispensing system inserting the probe into the internal reservoir of the liquid storage module of FIG. 30.

[0055] FIG. 41 illustrates an example of an alternative embodiment of a polarizer holder of the titer module of FIG. 14.

DETAILED DESCRIPTION

[0056] FIG. 1 is an isometric view of an example of a cell analysis system 100 that analyzes cell health of a plurality of cell samples. For a single cell sample, the cell analysis system 100 can measure cell count, cell viability, antibody concentration (e.g., protein titer), and other cell characteristics with minimal interaction from a user of the system.

[0057] The cell analysis system 100 includes connectivity⁷ to automated bioreactors and other systems and devices. The connectivity to the automated bioreactors and the other systems and devices can include electrical connectivity for sharing data, and can also include physical connectivity for liquid handling purposes. The cell analysis system 100 automates sample preparation, and minimizes sample volume requirements for measuring cell characteristics. The cell analysis system 100 provides remote access to data including the measured cell characteristics, supports multiple users at once, and is compatible with various information technology⁷ (IT) structures.

[0058] As shown in FIG. 1, the cell analysis system 100 includes a housing 102 that supports a work platform 300. The housing 102 includes a top cover 104 that can support a dispensing system 106 that will be described in more detail with reference to

FIGS. 2 and 3.

[0059] FIG. 2 is another isometric view of the cell analysis system 100 having the top cover 104 removed from the housing 102, and thereby exposing the dispensing system 106. FIG. 3 is a top view of the work platform 300 supported inside the housing 102. Referring now to FIGS. 2 and 3, the work platform 300 supports one or more tube racks that hold a plurality of containers containing cell samples and various types of reagents. In some instances, at least some of the containers are empty. The dispensing system 106 includes a probe 108 that is movably mounted within the housing 102 in the space above the work platform 300. The dispensing system 106 is an example of an automated pipetting robotic system.

[0060] The probe 108 is mounted for movement along three mutually perpendicular axes (e.g., X-axis, Y-axis, and Z-axis of a three-dimensional cartesian coordinate system). The three-dimensional movement allows a distal end of the probe 108, through which liquid aspiration and dispensing occurs, to access any container held on the work platform 300 inside the housing 102.

[0061] A proximal end of the probe 108 is fluidly connected to a bi-directional pump having a movable actuator that controls the mode of the pump. For example, a first mode can include aspirating and a second mode can include dispensing, and the movable actuator controls switching between the first and second modes, as well as a rate of liquid that is aspirated and dispensed under the first and second modes. As an example, the bi-directional pump can include a syringe pump. Movement of the probe 108 and the movable actuator is controlled by one or more step motors that operate under the control of a controller 1300 that is programmable.

[0062] As shown in FIG. 2, the housing 102 is dimensioned to have a width W, a depth D, and a height H. As an illustrative example, the width W is about 24 inches to about 36 inches, the depth D is about 24 inches to about 36 inches, and the height H is about 24 inches to about 36 inches. In some examples, the housing 102 is dimensioned to have a cube shape.

[0063] As shown in FIG. 3, the work platform 300 supports a sample transfer module 302, one or more mixing plates 304, a cell health module 306, one or more tip racks 308, one or more titer plates 310, a tip waste bin 312, a liquid storage module 314, sample inputs 316 such as tube trays and well plates, a metabolite module 318, and a titer module 400. The cell health module 306 measures cell health, including cell count and cell viability. The titer module 400 measures protein titer, and will now be described in more detail with reference to FIG. 4.

[0064] FIG. 4 schematically⁷ illustrates an example of the titer module 400 supported on the work platform 300. The titer module 400 includes optical components that are used to measure a concentration of an antibody present in a cell sample. For example, the titer module 400 measures a concentration of Immunoglobulin G (IgG) present in a sample of cells.

[0065] More specifically, the titer module 400 calculates a fluorescence polarization measurement for measuring the concentration of IgG protein in the sample of cells. Fluorescence polarization includes mixing the sample of cells with a fluorescence polarization assay, and subsequently measuring fluorescence polarization for determining the concentration of the IgG protein in the sample of cells. While the titer module 400 is described herein with reference to measuring IgG concentration, the titer module 400 and the measurement techniques described herein can be used to measure the concentrations of additional types of proteins and antibodies.

[0066] As shown in FIG. 4, the titer module 400 includes a light source 402 that emits light 404 toward a container 412 holding a solution of cells mixed with the fluorescence polarization assay. The fluorescence polarization assay binds with antibodies of interest (e.g.. IgG) produced by the cells. As discussed above, the dispensing system 106 of the cell analysis system 100 is automated to mix the fluorescence polarization assay together with the sample of cells in the container 412, such that the user of the system does not need to manually mix the solution in the container 412. In some examples, the container 412 is a cuvette, tube, and the like. [0067] The light source 402 emits the light 404 without polarization such that the light 404 is unpolarized light. In some examples, the light source 402 is a light-emitting diode (LED). In some examples, the titer module 400 includes a focusing lens 406 and a spectral filter 408 that respectively focus and filter the light 404 emitted from the light source 402.

[0068] The light 404 passes through an excitation polarizer 410 that polarizes the light 404 in a first direction 411. In some examples, the first direction 411 is in a linear direction. In the example shown in FIG. 4, the first direction 411 is vertically linear. In alternative examples, the first direction 411 is horizontally linear. Additional polarization directions are possible.

[0069] The light 404, once polarized in the first direction 411 , is absorbed by the solution of cells mixed with the fluorescence polarization assay in the container 412. This causes the solution in the container 412 to emit polarized fluorescence light 416. [0070] The polarized fluorescence light 416 can pass through a lens 414 for focusing after emission from the solution in the container 412. Afterwards, the polarized fluorescence light 416 alternately passes through a first detection polarizer 420 and a second detection polarizer 422. The first and second detection polarizers 420, 422 are mounted to a polarizer holder 418 controlled by the controller 1300 to alternate placement of the first and second detection polarizers 420, 422 in the path of the polarized fluorescence light 416.

[0071] The first detection polarizer 420 is polarized in a direction parallel to the direction of the excitation polarizer 410 (i.e., in the first direction 411). The first detection polarizer 420 restricts passage of the polarized fluorescence light 416 to the first direction 41 1.

[0072] The second detection polarizer 422 is polarized in a second direction 413 perpendicular to the first direction 411 of the excitation polarizer 410. The second detection polarizer 422 restricts passage of the polarized fluorescence light 416 to the second direction 413. Thereafter, the polarized fluorescence light 416 passes through a spectral filter 424 before detection by a detector 426. In some examples, the detector 426 a photomultiplier tube (PMT). The detector 426 converts the polarized fluorescence light 416 into voltage values for input into Equation 1 to determine a concentration of antibody produced by the same of cells. where IPAR is a voltage of parallel fluorescence detected from the solution in the container 412, IPER is a voltage of perpendicular fluorescence detected from the solution in the container 412. and FP is fluorescence polarization in milli-polarization units (mP). As an example, the voltages of IPAR and IPER detected by the detector 426 can range from about 0.02 volts to about 5.0 volts.

[0073] The measured fluorescence polarization (FP) is correlated with the concentration of antibody in the sample of cells. For example, a higher detected FP correlates to a higher concentration of antibody, and a lower detected FP correlates to a lower concentration of antibody. This is because a higher concentration of antibody will have increased binding with the fluorescence polarization assay such that the voltage of parallel fluorescence is larger, and the voltage of perpendicular fluorescence is smaller, which results in a larger detected FP.

[0074] A technical challenge with Equation 1 is that any error in measuring IPAR that is not present in IPER can cause an error in calculation of the fluorescence polarization (FP). For example, the FP calculation depends on the measured ratio IPER/ IPA . Any variation that affects IPAR and IPER proportionally is canceled out. However, errors such as signal intensity variation over the course of measuring the parallel fluorescence (IPAR) and the perpendicular fluorescence (IPER). as well as offset errors affecting both the perpendicular fluorescence (IPER) and the parallel fluorescence (IPAR), do not get canceled out and can cause significant errors in the FP calculation, and thereby causing errors when calculating a concentration of antibody in a sample of cells.

[0075] Sources of signal intensity variation can include, without limitation, intensity fluctuation and drift of the light source 402, electrical response, dye bleaching, and non-uniform fluid and diffusion in the container 412. Additional sources of errors are possible. Sources of offset noise can include, without limitation, electrical circuit noise and ambient light.

[0076] FIG. 5 graphically illustrates an example of a plot 500 showing detected light intensity⁷ drift in the titer module 400 causing an error in the FP calculation, and miscalculation of the concentration of antibody in the sample of cells. The plot 500 includes a light intensity (Y -axis) measured by the detector 426 over time (X-axis). In this example, the light intensity is measured without any solution of cells and fluorescence polarization assay in the container 412, such that the drift of the light intensity is not caused by the solution.

[0077] In this example, the light intensity of the light source 402 is expected to have a constant value of 3.5V. Thus, the ratio between the IPER and IPAR fluorescence should be 1: 1 (e.g., 3.5V:3.5V) because there is no sample of cells containing antibodies in the container 412.

[0078] However, the actual light intensity shown in the plot 500 exhibits a voltage drift that causes an error in the ratio between IPER and IPAR fluorescence. In this example, a measurement cycle is performed where the IPER fluorescence is measured in a first phase (i. e. , using the second detection polarizer 422), and thereafter the IPAR fluorescence is measured in a second phase (i.e., using the first detection polarizer 420). Each of the IPER and IPAR fluorescence phases include two measurements. For example, the IPER fluorescence includes a first measurement of 3.60V and a second measurement of 3.62V, and the IPA fluorescence includes a third measurements of 3.64V and a fourth measurement of 3.66V. The IPER fluorescence is calculated as an average of the first and second measurements (i.e., 3.61V), and the IPAR fluorescence is calculated as an average of the third and fourth measurements (i.e., 3.65V). This results in a ratio of 3.61 :3.65 between the IPER and IPAR fluorescence, which is about a 1% error caused by the drift of the light source 402.

[0079] FIG. 6 graphically illustrates a plot 600 showing simulated fluorescent polarization measurement errors that result from the measurement sequence of FIG. 5. As shown in FIG. 6, the measurement errors are significantly greater for lower mP values such as mP values less than 200 units. Thus, lower concentrations of antibodies in the samples held by the container are especially sensitive to signal intensity variation and noise in the titer module 400.

[0080] In some instances, measurement errors in the ratio between the IPER and IPAR fluorescence from signal intensity variation and noise are reduced by implementing complicated electrical circuit designs and temperature controlled light sources and detectors in the titer module. However, such solutions are expensive, have low reliability, can increase the size of the titer module, and slow dow n the warmup time for using the device.

[0081] FIG. 7 schematically illustrates an example of a method 700 of measuring a concentration of an antibody in a cell sample. The method 700 uses the optical components of the titer module 400 (show n in FIG. 4) to calculate the concentration of the antibody in the cell sample. In some examples, the method 700 is performed to measure a concentration of Immunoglobulin G (IgG) in a solution containing a fluorescence polarization assay is mixed in the container 412 using the dispensing system 106 of the cell analysis system 100.

[0082] The method 700 reduces errors from signal intensity’ variation and noise without requiring changes to the optical components and hardware of the titer module

400. Instead, the method 700 is a software solution that improves the functioning of the titer module 400 by reducing these types errors to improve the accuracy of the antibody concentration calculation.

[0083] The method 700 includes an operation 702 of performing a measurement cycle. Operation 702 includes using the optical components of the titer module 400 to take a first set of measurements of light fluoresced from the solution in the first direction 411, and to take a second set of measurements of light fluoresced from the solution in the second direction 413. The first and second sets of measurements alternate with one another in the measurement cycle.

[0084] FIG. 8 schematically illustrates an example of a method 800 of performing the measurement cycle in operation 702 of the method 700. FIG. 9 schematically illustrates an example of a measurement cycle 900 performed in accordance with the method 800.

[0085] Referring now to FIGS. 8 and 9, the method 800 includes a step 802 of measuring a first sampling phase A of the light fluoresced from the container 412 in the first direction 411 before a midpoint 902 of the measurement cycle 900. Next, the method 800 includes a step 804 of measuring a second sampling phase B of the light fluoresced from the container 412 in the second direction 413 before the midpoint 902 of the measurement cycle 900.

[0086] As further shown in FIGS. 8 and 9, the method 800 includes a step 806 of measuring a third sampling phase C of the light fluoresced from the container 412 in the second direction 413 after the midpoint 902 of the measurement cycle 900. Next, the method 800 includes a step 808 of measuring a fourth sampling phase D of the light fluoresced from the container 412 in the first direction 411 after the midpoint 902 of the measurement cycle 900.

[0087] The measurement cycle 900 includes at least one sampling phase in the first direction 411 and at least one sampling phase in the second direction 413 before the midpoint. The measurement cycle includes at least one sampling phase in the first direction 411 and at least one sampling phase in the second direction 413 after the midpoint of the measurement cycle.

[0088] During the measurement cycle 900, the polarizer holder 418 is controlled by the controller 1300 to switch at a transition point 904 from the first detection polarizer 420 polarized in a direction parallel to the direction of the excitation polarizer 410 to the second detection polarizer 422 polarized in a direction perpendicular to the direction of the excitation polarizer 410. The transition point 904 occurs between the first and second sampling phases A, B. Also, during the measurement cycle 900. the polarizer holder 418 is controlled by the controller 1300 to switch at a transition point 906 from the second detection polarizer 422 (which is polarized in a direction perpendicular to the direction of the excitation polarizer 410) to the first detection polarizer 420 (which is polarized in a direction parallel to the direction of the excitation polarizer 410). The transition point 906 occurs between the third and fourth sampling phases C, D.

[0089] As further shown in FIG. 9, the sampling phases A-D each include voltage measurements of fluoresced light from a plurality of light pulses 908 emitted by the light source 402. For each of the light pulses 908. the detector 426 obtains a plurality of voltage measurements 910. For example, the plurality of voltage measurements 910 from each of the light pulses 908 includes a first set of voltage measurements 910a when the light source 402 is turned on, and a second set of voltage measurements 910b when the light source 402 is turned off. Steps 802-808 for measuring the first, second, third, and fourth sampling phases A, B C, D, respectively, can each include performing additional operations showm in FIG. 12.

[0090] FIG. 12 schematically illustrates a method 1200 of measuring a sampling phase performed in the measurement cycle of FIGS. 8-10. Referring now to FIGS. 9 and 12, the method 1200 includes an operation 1202 of calculating an average of the first set of voltage measurements 910a when the light source 402 is turned on. Next, the method 1200 includes an operation 1204 of calculating an average of the second set of voltage measurements 910b when the light source 402 is turned off. Next, the method 1200 includes an operation 1206 of determining a voltage value for each of the light pulses 908 in the sampling phase by subtracting the average of the second set of voltage measurements 910b from the average of the first set of voltage measurements 910a. Next, the method 1200 can include an operation 1208 of determining a voltage value for the sampling phase by calculating an average of the voltage values of the plurality of light pulses 908 in the sampling phase.

[0091] Referring back to FIG. 7, the method 700 includes an operation 704 of calculating a first average of the first and fourth sampling phases A, D. As show n in FIG. 9, the first sampling phase A includes light fluoresced in the first direction 411 before the midpoint 902 of the measurement cycle 900. The fourth sampling phase D includes light fluoresced in the first direction 411 after the midpoint 902 of the measurement cycle 900.

[0092] Next, the method 700 includes an operation 706 of calculating a second average of the second and third sampling phases B, C. As described above, the second sampling phase B includes light fluoresced from the container in the second direction 413 before the midpoint 902 of the measurement cycle 900. The third sampling phase C includes light fluoresced from the container in the second direction 413 after the midpoint 902 of the measurement cycle 900.

[0093] The method 700 includes an operation 708 of determining a concentration of the antibody based on a ratio of the first and second averages. For example, the first average is the voltage of parallel fluorescence (IPAR), the second average is the voltage of perpendicular fluorescence (IPF.R), and the concentration of the antibody is calculated using Equation 1.

[0094] FIG. 10 graphically illustrates an example of a plot 1000 showing how the method 700 eliminates errors in calculating the unit of polarization measurement (mP) used for determining a concentration of antibody in a sample of cells. The plot 1000 includes a light intensity (Y -axis) measured by the detector 426 over time (X-axis). Like in the example plot in FIG. 5, the plot 1000 shows the light source 402 exhibits drift from an expected value of 3.5V. The light intensity is measured without absolution of cells and fluorescence polarization assay in the container 412, such that the drift of the light intensity is not caused by the solution.

[0095] As shown in FIG. 10, a measurement cycle is performed where the first sampling phase A is measured for the light fluoresced in the first direction (3.55V) before the midpoint M, the second sampling phase B is measured for the light fluoresced in the second direction (3.59V) before the midpoint M, the third sampling phase C is measured for the light fluoresced in the second direction (3.61V) after the midpoint M, and the fourth sampling phase D is measured for the light fluoresced in the first direction (3.65V) after the midpoint M. The first average of the first and fourth sampling phases A, D is calculated as 3.6V. The second average of the second and third sampling phases B, C is calculated as 3.6V. This results in a ratio of 3.6:3 6 between the IPER and IPAR fluorescence, w hich eliminates the error caused by the drift of the light source 402 (see, for comparison, the plot 500 shown in FIG. 5). Thus, the measurement cycle performed in the method 800 reduces errors, and even in some instances eliminates the errors, when measuring a concentration of antibody in a cell sample using fluorescence polarization.

[0096] FIG. 11 graphically illustrates a plot 1 100 showing a reduction in the simulated fluorescent polarization measurement errors that result from the measurement cycle shown in FIG. 8-10. Referring now to FIGS. 6 and 11, the plot 1100 shows that the measurement errors are significantly less for lower mP values (e.g.. mP values less than 200 units) than the measurement errors shown in the plot 600 when a traditional measurement sequence is performed. The plot 1100 shows that sensitivity to signal intensity variation and noise in the titer module 400 is significantly reduced for lower concentrations of antibodies.

[0097] FIG. 13 schematically illustrates an example of the controller 1300 of the cell analysis system 100 that can be used to implement aspects described herein, including the features of the titer module 400. As shown in FIG. 13, the controller 1300 includes one or more processing devices 1302, a memory storage device 1304, and a system bus 1306 that couples the memory storage device 1304 to the one or more processing devices 1302. The one or more processing devices 1302 can include central processing units (CPU). In some instances, the one or more processing devices 1302 are part of a processing circuitry' having a memory' for storing instructions which, when executed by the processing circuitry, cause the processing circuitry to perform the various aspects, features, and functionalities described herein.

[0098] As shown in FIG. 13, the memory storage device 1304 can include a random-access memory (“RAM”) 1308 and a read-only memory (“ROM”) 1310. Basic input and output logic having basic routines that help to transfer information between elements within the controller 1300. such as during startup, can be stored in the ROM 1310.

[0099] The controller 1300 can also include a mass storage device 1312 that can include an operating system 1314 and store software instructions and data 1316. The mass storage device 1312 is connected to the processing device 1302 through the system bus 1306. The mass storage device 1312 and associated computer-readable data storage media provide non-volatile, non-transitory storage for the controller 1300.

[0100] Although the description of computer-readable data storage media contained herein refers to the mass storage device 1312, it should be appreciated by those skilled in the art that computer-readable data storage media can be any available non- Iran si toiy . physical device or article of manufacture from which the controller 1300 can read data and/or instructions. The computer-readable storage media can be comprised of entirely non-transitory media. The mass storage device 1312 is an example of a computer-readable storage device.

[0101] Computer-readable data storage media include volatile and non-volatile, removable, and non-removable media implemented in any method or technology for storage of information such as computer-readable software instructions, data structures, program modules or other data. Example types of computer-readable data storage media include, but are not limited to, RAM, ROM, EPROM, EEPROM, flash memory or other solid-state memory technology, or any other medium which can be used to store information, and which can be accessed by the device.

[0102] The controller 1300 can operate in a networked environment using logical connections to the other devices through the network 1320. The controller 1300 connects to the network 1320 through a network interface unit 1318 connected to the system bus 1306. The network interface unit 1318 can also connect to additional types of communications networks and devices, including through Bluetooth, Wi-Fi, and cellular telecommunications networks including 4G and 5G networks. The network interface unit 1318 can connect the controller 1300 to additional networks, systems, and devices. The controller 1300 also includes an input/output unit 1322 for receiving and processing inputs and outputs from peripheral devices.

[0103] The mass storage device 1312 and the RAM 1308 can store software instructions and data. The software instructions can include an operating system 1314 suitable for controlling the operation of the cell analysis system 100. The mass storage device 1312 and/or the RAM 1308 can also store the software instructions and data 1216, which when executed by the processing device 1302, provide the functionality of the cell analysis system 100 discussed herein.

[0104] FIG. 14 is an isometric view of an example of the titer module 400 that can be used in the cell analysis system 100 (e.g., see also FIGS. 3 and 4). FIG. 15 is an isometric view of the titer module 400 with a portion of a housing 401 removed exposing internal components of the titer module. FIG. 16 is an isometric cross- sectional view taken along a horizonal axis of the titer module 400. Referring now to FIGS. 14-16. the internal components of the titer module 400 include an excitation assembly 403 and a detection assembly 405. [0105] The excitation assembly 403 includes a first optical cover 407 that houses at least partially the light source 402 and the excitation polarizer 410. The detection assembly 405 includes a second optical cover 409 that houses at least partially the detector 426, the polarizer holder 418 and the first and second detection polarizers 420, 422.

[0106] As will be described in more detail, the polarizer holder 418 is operated by the controller 1300 to precisely align the detection polarization axes of the first and second detection polarizers 420, 422 to be respectively parallel and perpendicular to the excitation polarization axis of the excitation polarizer 410. This arrangement is generally more precise than one where the polarizer axis is rotated, which can generally result in higher variability of the polarizer in the light path. The polarizer holder 418 is directed to the technical problem of repeatably and precisely switching between the first and second detection polarizers 420, 422 on the detection leg of the optical path in the titer module 400.

[0107] FIG. 17 is an isometric view of the titer module 400 with first and second optical covers 407, 409 removed exposing the optical components of the titer module. FIG. 18 is a right side view of the optical components of the titer module 400. FIG. 19 is a left side view of the optical components of the titer module 400. The optical components of the titer module 400 shown in FIGS. 17-19 are substantially similar to the optical components schematically shown in FIG. 4. For example, the titer module 400 includes the light source 402 that emits light toward the container 412 holding a cell culture of IgG protein mixed with the fluorescence polarization assay. In some examples, the container 412 is a cuvette, tube, and the like.

[0108] The light source 402 emits the light without polarization such that the light is unpolarized light. In some examples, the light source 402 is a light-emitting diode (LED). In some examples, the titer module 400 includes an optical holder 460 that includes the focusing lens 406 and the spectral filter 408 that respectively focus and filter the light emitted from the light source 402.

[0109] The light passes through an excitation polarizer 410 that polarizes the light in the first direction 411 (see FIG. 4). The light, once polarized in the first direction 411, is absorbed by the solution of cells mixed with the fluorescence polarization assay in the container 412. This causes the solution in the container 412 to emit polarized fluorescence light. [0110] The polarized fluorescence light passes through a lens 414 and an aperture 415 after emission from the container 412. The light then passes through the first detection polarizer 420 or the second detection polarizer 422, which are mounted to the polarizer holder 418. As will be described in more detail, the polarizer holder 418 is powered by a motor 428 to rotate, which causes alternate placement of the first and second detection polarizers 420, 422 in the path of the polarized fluorescence light emitted from the solution in the container 412.

[OHl] As discussed above, the first detection polarizer 420 is polarized in a direction parallel to the direction of the excitation polarizer 410, while the second detection polarizer 422 is polarized in a direction perpendicular to the direction of the excitation polarizer 410.

[0112] The polarized fluorescence light then passes through a spectral filter 424 before reaching the detector 426. In some examples, the detector 426 a photomultiplier tube (PMT). As described above, the detector 426 converts the polarized fluorescence light into voltage values for input into Equation 1 to determine a concentration of antibody produced by the cell culture.

[0113] FIG. 20 is an isometric cross-sectional view taken along a vertical axis of the titer module 400. FIG. 21 is a cross-sectional right side view of the titer module 400. FIG. 22 is a cross-sectional left side view of the titer module 400. Referring now to FIGS. 20-22, the polarizer holder 418 is connected to a drive shaft 434 of the motor 428. In some examples, the motor 428 is a stepper motor (also known as step motor or stepping motor), or similar type of electric motor. In other examples, the motor 428 is a solenoid. The motor 428 is mounted to an underside of an optics plate 419 that supports the optical components of the titer module 400.

[0114] The controller 1300 controls the motor 428 to rotate the polarizer holder 418 about an axis of rotation R-R in a clockwise direction DI and a counterclockwise direction D2 (see FIG. 27), which causes alternate placement of the first and second detection polarizers 420. 422 in an optical path of the polarized fluorescence light emitted from the solution in the container 412 before the light reaches the detector 426. In some examples, the controller 1300 controls the motor 428 to rotate the polarizer holder 418 about 90 degrees in the clockwise direction DI, and about 90 degrees in the counterclockwise direction D2 about the axis of rotation R-R. [0115] In an alternative embodiment, FIG. 41 illustrates an example of a polarizer holder 418a that includes a rotation mount 462 and an electromagnetic drive 464 that can be used to position a detection polarizer 466 in the path of the light fluoresced from the container 412. In some examples, the electromagnetic drive 464 drives the rotation mount 462 to rotate the detection polarizer 466 about an axis parallel to the light beam entering the detection polarizer. In this alternative embodiment, the electromagnetic drive 464 rotates the detection polarizer 466 to a first position such that the detection polarizer 466 has a polarity that is parallel to the polarity of the excitation polarizer 410, and rotates the detection polarizer 466 to a second position such that the detection polarizer 466 has a polarity' that is perpendicular to the polarity of the excitation polarizer 410. In this example, the electromagnetic drive 464 can rotate the detection polarizer about 90 degrees between the first and second positions. In this example, the electromagnetic drive 464 includes magnets 468 positioned next to the rotation mount 462, and the magnets 468 drive the rotation mount 462 to rotate the detection polarizer 466 to the desired rotational position. In some examples, the magnets 468 surround or at least partially surround the rotation mount 462 and the detection polarizer 466. The electromagnetic drive 464 can provide more accuracy than rack and pinion mechanisms that are used to position detection polarizers.

[0116] FIGS. 23 and 24 are isometric views of the polarizer holder 418, the optics plate 419, and the detector 426 of the titer module 400. FIGS. 25 and 26 are exploded views of the polarizer holder 418. FIG. 27 is a top view of the polarizer holder 418. Referring now to FIGS. 23-27, the polarizer holder 418 has a turret-like arrangement. The polarizer holder 418 includes first and second side surfaces 430, 432. In some examples, the first and second side surfaces 430, 432 are perpendicular with respect to each other. The polarizer holder 418 further includes a curved surface 431 that connects the first and second side surfaces 430, 432. An exterior of the polarizer holder 418 includes the first and second side surfaces 430, 432 and the curved surface 431.

[0117] The first detection polarizer 420 is mounted to a first side surface 430 of the polarizer holder 418. and the second detection polarizer 422 is mounted to a second side surface 432 of the polarizer holder 418. For example, the first side surface 430 includes a recessed portion 435 into which the first detection polarizer 420 is placed. Similarly, the second side surface 432 includes a recessed portion 435 into which the second detection polarizer 422 is placed. As shown in FIG. 27, the first and second detection polarizers 420, 422 protrude beyond the respective first and second side surfaces 430, 432 when placed inside the recessed portions 435.

[0118] As shown in FIGS. 25-27, biasing elements 436 are used to hold the first and second detection polarizers 420, 422 inside the recessed portions 435 of the first and second side surfaces 430, 432, respectively. Fasteners 438, such as screws, can be threaded through apertures 440 on the biasing elements 436 into holes 441 on the first and second side surfaces 430, 432 to attach the biasing elements 436 to the first and second side surfaces 430, 432, and thereby secure the first and second detection polarizers 420, 422 in the recessed portions 435. In some examples, the biasing elements 436 are retaining springs.

[0119] The biasing elements 436 are flexible such that they are configured to flex around the edges of the first and second detection polarizers 420, 422 to secure the first and second detection polarizers 420, 422 in place. In some examples, the biasing elements 436 includes cutouts 439 to increase their flexure. In some examples, cutouts 439 are provided toward a top and a bottom of each biasing element 436 to increase the flexure of the biasing elements 436 around the tops and bottoms of the first and second detection polarizers 420, 422.

[0120] The biasing elements 436 include apertures 442 that allow the polarized fluorescence light emitted from the solution in the container 412 to pass through the first and second detection polarizers 420, 422. The recessed portions 435 each include an aperture 437 (see FIG. 25) that aligns with a respective aperture 444 on the curved surface 431 (see FIG. 26) allowing the polarized fluorescence light to pass through the polarizer holder 418, and reach the detector 426.

[0121] As shown in FIG. 16, the curved surface 431 of the polarizer holder 418 aligns with a curved wall 417 of the second optical cover 409 to minimize a space between the polarizer holder 418 and the curved wall 417. This can help mitigate stray light from entering the first and second detection polarizers 420, 422 and reaching the detector 426. which can interfere with the voltage values detected by the detector 426. Thus, the curved surface 431 of the polarizer holder 418 can reduce noise in the voltage values detected by the detector 426.

[0122] FIG. 28 is an isometric view of the optics plate 419 and the motor 428 of the titer module 400 with the polarizer holder removed therefrom. FIG. 29 is a top view of the optics plate 419. Referring now to FIGS. 28 and 29. as discussed above, the polarizer holder 418 is fixed directly to the drive shaft of the motor 428, and the motor is mounted to the underside of the optics plate 419. The polarizer holder 418 includes a dowel pin 446 on an underside of the holder. The dowel pin 446 glides inside a groove 448 of the optics plate 419 as the polarizer holder 418 rotates about the axis of rotation R-R in the clockwise direction DI and the counterclockwise direction D2 (see FIGS. 20-22 and 27). As shown in FIGS. 28 and 29, the groove 448 is curved along the axis of rotation R-R.

[0123] The dowel pin 446 contacts first and second stops 450, 4 1 in the groove 448 at the end of rotational travel in each of the clockwise direction DI and the counterclockwise direction D2. For example, when the polarizer holder 418 rotates 90 degrees in the clockwise direction DI to position the first detection polarizer 420 into the optical path of the light, the dowel pin 446 contacts the first stop 450 at a distal end of the groove 448 to prevent further rotation of the polarizer holder 418. Similarly, when the polarizer holder 418 rotates 90 degrees in the counterclockwise direction D2 to position the second detection polarizer 422 into the optical path of the light, the dowel pin 446 contacts the second stop 451 at an opposite distal end of the groove 448 to prevent further rotation of the polarizer holder 418.

[0124] Each of the first and second stops 450, 451 is associated with a position of the polarizer holder 418. For example, the first stop 450 is associated with a parallel polarizer position 454 when the first detection polarizer 420 is positioned into the optical path of the light (see FIG. 27). The second stop 451 is associated with a perpendicular position 456 when the second detection polarizer 422 is positioned into the optical path of the light.

[0125] As further shown in FIGS. 28 and 29, the optics plate 419 includes magnets 452 positioned next to each of the first and second stops 450, 451 . The dowel pin 446 is made of a ferromagnetic material such as steel such that a magnet 452 attract the dowel pin 446 when positioned close to the first stop 450 at the end of the rotational travel in the clockwise direction DI, and a magnet 452 attracts the dowel pin 446 when positioned close the second stop 451 at the end of the rotational travel in the counterclockwise direction D2.

[0126] The controller 1300 is programmed to power off the motor 428 at the end of the rotational travel in the clockwise and counterclockwise directions DI, D2 such that the magnets 452 pull the dowel pin 446 firmly up against the first and second stops 450. 451. The magnets 452 ensure a high degree of repeatability between the parallel and perpendicular polarizer positions and improves the overall precision and repeatability of the titer module 400.

[0127] The arrangement of the polarizer holder 418 which rotates in the clockwise and counterclockwise directions DI, D2 to alternately place the first and second detection polarizers 420. 422 in the optical path of the light emission from the solution in the container 412 reduces the space needed for the polarizer holder 418 on the optics plate 419 of the titer module 400. Also, the arrangement of the polarizer holder 418 mitigates stray light from passing through the first and second detection polarizers 420, 422, and ensures that the alignment of the first and second detection polarizers 420, 422 remains fixed relative to the excitation polarization axis from the excitation assembly 403 of the titer module 400.

[0128] FIG. 30 is an isometric view of the liquid storage module 314 of the cell analysis system 100 (see also FIG. 3). In FIG. 30, the liquid storage module 314 is shown in a closed position. The liquid storage module 314 can be used in combination with the titer module 400. For example, the liquid storage module 314 can house a liquid such as a diluent used by the titer module 400. The liquid storage module 314 is designed to prevent evaporation of the liquid diluent (especially liquid diluents sensitive to light and air exposure), while allowing efficient loading and pipetting of the liquid diluent. As an illustrative example, the liquid storage module 314 can limit evaporation to be less than about 1 .5% by volume for an onboard storage life of about 31 days inside the cell analysis system 100.

[0129] FIGS. 31 and 32 are isometric views of the liquid storage module 314 shown in an opened position. Referring now to FIGS. 30-32, the liquid storage module 314 includes a base 3002 that has an interior volume 3004 for holding an internal reservoir 3006. A user can access the internal reservoir 3006 (e.g., to load the liquid diluent into the internal reservoir 3006) by manually opening a primary lid 3008. The internal reservoir 3006 is re-usable and replaceable. For example, the internal reservoir 3006 can be removed from the interior volume 3004 such as for washing or replacing it with another internal reservoir (e.g., one that is new or clean).

[0130] In some examples, the internal reservoir 3006 includes a single well having a volume of about 40 mL. In some examples, the internal reservoir 3006 has a V-shaped bottom. Once the diluent is loaded into the internal reservoir 3006, the user can manually close the primary' lid 3008. During operation of the cell analysis system 100, the primary’ lid 3008 remains closed.

[0131] The primary lid 3008 can be manually pivoted about a hinge 3012 to move betyveen the closed position (FIG. 30) and the opened position (FIGS. 31 and 32). The liquid storage module 314 includes a gasket 3014 that surrounds the interior volume 3004 yvhere the internal reservoir 3006 is held. The gasket 3014 can be made of ethylene propylene diene monomer (EPDM) rubber. The gasket 3014 engages an internal surface 3016 of the primary lid 3008 when the primary lid 3008 is in the closed position to seal around the internal reservoir 3006.

[0132] The primary lid 3008 includes one or more first magnets 3018 that are magnetically attracted to one or more second magnets 3020 positioned on the base 3002. The attraction of the one or more first magnets 3018 to the one or more second magnets 3020 can hold the primary lid 3008 shut once the lid is pivoted about the hinge 3012 into the closed position.

[0133] FIG. 33 is another isometric view of the liquid storage module 314 showing the primary lid 3008 in the closed position. Referring now to FIGS. 30 and 33, the liquid storage module 314 includes a secondary lid 3010 attached to the primary lid 3008. The secondary' lid 3010 is controlled by the controller 1300 to open and close as needed for the probe 108 of the dispensing system 106 (see FIG. 2) to access to the internal reservoir 3006. For example, the controller 1300 opens the secondary lid 3010 during pipetting, and closes the secondary lid 3010 after pipetting is completed to seal the diluent inside the internal reservoir 3006, and thereby prevent evaporation of the diluent during use of the cell analysis system 100.

[0134] As shown in FIG. 33, yvhen the secondary lid 3010 is opened, a port 3022 on the primary lid 3008 is exposed. The probe 108 of the dispensing system 106 can be inserted through the port 3022 to access the internal reservoir 3006 yvithout having to open the primary lid 3008. In some examples, the port 3022 is sized for a 55uL or 230uL tapered pipette tips to pass through the port. Such pipettes are not typically viable for use with solid septum caps.

[0135] The secondary lid 3010 has a gasket 3024 to seal the port 3022 when the secondary/ lid 3010 is in the closed position to prevent evaporation of the diluent contained inside the internal reservoir 3006. In some examples, the gasket 3024 is made of polyethy lene (PE) foam. [0136] FIG. 34 is another isometric view of the liquid storage module 314 showing the primary lid 3008 in the opened position. Referring now to FIG. 34, a magnet 3026 is mounted to the primary lid 3008 that attracts a ferrous element 3028 on the secondary lid 3010 to close the secondary lid 3010 shut. For example, a hinge 3030 of the secondary⁷ lid 3010 can include the ferrous element 3028 that is attracted to the magnet 3026 to close the secondary lid 3010. In alternative examples, the magnet 3026 is included on the secondary lid 3010, and the ferrous element 3028 is included on the primary lid 3008. The magnet 3026 and the ferrous element 3028 keep the secondary' lid 3010 closed shut.

[0137] A motor 3032 is mounted to the internal surface 3016 of the primary lid 3008. The secondary lid 3010 is connected to the motor 3032. The motor 3032 can include a stepper motor, or similar type of electric motor. The motor 3032 is controlled by the controller 1300 to move the secondary lid 3010 between opened and closed states. The motor 3032 can utilize an integrated encoder to track the opened and closed states of the secondary lid 3010.

[0138] FIG. 35 is an isometric view of the secondary lid 3010. FIG. 36 is a front view of the secondary lid 3010. FIG. 37 is a side view of the secondary' lid 3010. FIG. 38 is a bottom view of the secondary' lid 3010. Referring now to FIGS. 35-38, the secondary' lid 3010 includes a top portion 3040, and a hinge 3042 that extends from the top portion. The top portion 3040 covers the port 3022 when the secondary lid 3010 is in the closed state. The hinge 3042 is connected to the motor 3032. For example, the hinge 3042 includes a first aperture 3044 that can be used to connect the secondary' lid 3010 to a drive shaft of the motor 3032. The hinge 3042 can also include a second aperture 3046 such as to attach the ferrous element 3028 (e.g., a screw) that is atached to the magnet 3026 on the primary lid 3008 to keep the secondary' lid 3010 closed shut. [0139] In some examples, the secondary' lid 3010 includes a plunger 3048 extends from a botom surface 3050 of the top portion 3040 such that the plunger is inserted inside the port 3022 when the secondary lid 3010 is in the closed state. Additionally, the gasket 3024 can be atached around the plunger 3048 to seal the port 3022 and mitigate evaporation of the diluent.

[0140] FIG. 39 is an isometric view inside the cell analysis system 100 showing the dispensing system 106 positioning the probe 108 behind the liquid storage module 324.

FIG. 40 is an isometric view inside the cell analysis system 100 showing the dispensing system 106 and the liquid storage module 324 with the secondary lid 3010 in the opened state The design of the liquid storage module 324, which includes a low profile when the primary lid 3008 is in the closed position, and the secondary lid 3010 that automatically opens and closes as needed, allows the dispensing system 106 to move the probe 108 freely above the work platform 300 inside the cell analysis system 100, such that the probe 108 can access labware placed behind the liquid storage module 324 without colliding with the liquid storage module 324. Also, the design of the liquid storage module 324 allows the dispensing system 106 to fully extend the probe 108, such as a 50uL or 230uL pipette, through the port 3022 to reach the bottom of the internal reservoir 3006 and aspirate the diluent, while also mitigating evaporation of the diluent during use of the cell analysis system 100 by causing the secondary lid 3010 to close and seal the port 3022 after the diluent is aspirated.

[0141] The various embodiments described above are provided by way of illustration only and should not be construed to be limiting in any way. Various modifications can be made to the embodiments described above without departing from the true spirit and scope of the disclosure.

[0142] Embodiments of the disclosure can be described with reference to the following numbered clauses, with preferred features laid out in the dependent clauses:

1. A method of fluorescence polarization for measuring a concentration of an antibody in a sample, the method comprising: performing a measurement cycle measuring a first set of sampling phases of light fluoresced in a first direction and a second set of sampling phases of the light fluoresced in a second direction, at least one sampling phase of the light fluoresced in the second direction occurring between sampling phases of the light fluoresced in the first direction; calculating a first value of the first set of sampling phases; calculating a second value of the second set of sampling phases; and determining the concentration of the antibody based on a function of the first and second values.

2. The method of clause 1, wherein a first sampling phase of the first set of sampling phases of the light fluoresced in the first direction occurs before a midpoint of the measurement cycle and a second sampling phase of the first set of sampling phases of the light fluoresced in the first direction occurs after a midpoint of the measurement cycle.

3. The method of clause 1, wherein each sampling phase includes voltage measurements of fluoresced light from a plurality of light pulses emitted by a light source.

4. The method of clause 3, further comprising: obtaining a plurality of voltage measurements from each light pulse.

5. The method of clause 4. wherein the plurality of voltage measurements from each light pulse includes a first set of voltage measurements when the light source is turned on, and a second set of voltage measurements when the light source is turned off.

6. The method of clause 5. further comprising: calculating a first average of the first set of voltage measurements; calculating a second average of the second set of voltage measurements; and determining a light pulse differential value for each light pulse by subtracting the second average from the first average.

7. The method of clause 6, further comprising: determining an average light pulse differential for a sampling phase by calculating an average of the light pulse differentials from the sampling phase.

8. The method of clause 7, further comprising: determining a first polarization value by calculating an average of the average light pulse differentials for the first set of sampling phases of the light fluoresced in the first direction.

9. The method of clause 8, further comprising: determining a second polarization value by calculating an average of the average light pulse differentials for the second set of sampling phases of the light fluoresced in the second direction. 10. The method of clause 9, further comprising: determining a concentration value by subtracting the second polarization value from the first polarization value, and dividing by a sum of the first and second polarization values.

11. The method of clause 1. wherein the antibody is Immunoglobulin G (IgG).

12. A fluorescence polarization system for measuring a concentration of an antibody in a sample, the system comprising: a light source; a first polarizing filter causing light emitted from the light source to be polarized in a first direction; a container holding the sample mixed with a fluorescence polarization assay, the container receiving the light polarized in the first direction; movable second and third polarizing filters, the second polarizing filter restricting passage of light fluoresced from within the container to the first direction, and the third polarizing filter restricting the passage of the light fluoresced from within the container to a second direction, the second being substantially direction being perpendicular to the first direction; a detector for measuring the light fluoresced in the first direction and the light fluoresced in the second direction; and a processing circuitry having a memory for storing instructions which, when executed by the processing circuitry, cause the processing circuitry to: perform a measurement cycle measuring a first set of sampling phases of the light fluoresced in the first direction and a second set of sampling phases of the light fluoresced in the second direction, at least one sampling phase of the light fluoresced in the second direction occurring between sampling phases of the light fluoresced in the first direction; calculate a first value of the first set of sampling phases; calculate a second value of the second set of sampling phases; and determine the concentration of the antibody based on a function of the first and second values. 13. The system of clause 12. wherein a first sampling phase of the first set of sampling phases of the light fluoresced in the first direction occurs before a midpoint of the measurement cycle and a second sampling phase of the first set of sampling phases of the light fluoresced in the first direction occurs after a midpoint of the measurement cycle.

14. The system of clause 13, wherein each sampling phase includes voltage measurements of fluoresced light from a plurality of light pulses emitted by the light source.

15. The system of clause 14, wherein the instructions, when executed by the processing circuitry, further cause the processing circuitry to: obtain a plurality of voltage measurements from each light pulse.

16. The system of clause 15, wherein the plurality of voltage measurements from each light pulse includes a first set of voltage measurements when the light source is turned on, and a second set of voltage measurements when the light source is turned off.

17. The system of clause 16. wherein the instructions, when executed by the processing circuitry, further cause the processing circuitry to: calculate a first average of the first set of voltage measurements; calculate a second average of the second set of voltage measurements; and determining a light pulse differential value for each light pulse by subtracting the second average from the first average.

18. The system of clause 17, wherein the instructions, when executed by the processing circuitry, further cause the processing circuitry to: determine an average light pulse differential for a sampling phase by calculating an average of the light pulse differentials from the sampling phase.

19. The system of clause 18. wherein the instructions, when executed by the processing circuitry, further cause the processing circuitry to: determine a first polarization value by calculating an average of the average light pulse differentials for the first set of sampling phases of the light fluoresced in the first direction.

20. The system of clause 19, wherein the instructions, when executed by the processing circuitry, further cause the processing circuitry to: determine a second polarization value by calculating an average of the average light pulse differentials for the second set of sampling phases of the light fluoresced in the second direction.

21. The system of clause 20. wherein the instructions, when executed by the processing circuitry, further cause the processing circuitry to: determine a concentration value by subtracting the second polarization value from the first polarization value, and dividing by a sum of the first and second polarization values.

22. The system of clause 12, wherein the antibody is Immunoglobulin G (IgG).

23. A method of fluorescence polarization for measuring a concentration of an antibody in a cell sample, the method comprising: performing a measurement cycle of light fluoresced from within the cell sample mixed with a fluorescence polarization assay, the measurement cycle including the following order of measurements:

(1) measuring a first sampling phase of light fluoresced in a first direction before a midpoint of the measurement cycle;

(2) measuring a second sampling phase of light fluoresced in a second direction before the midpoint of the measurement cycle, the second direction being perpendicular to the first direction;

(3) measuring a third sampling phase of the light fluoresced in the second direction after the midpoint of the measurement cycle; and

(4) measuring a fourth sampling phase of the light fluoresced in the first direction after the midpoint of the measurement cycle; calculating a first average of the first and fourth sampling phases; calculating a second average of the second and third sampling phases; and determining the concentration of the antibody based on a function of the first and second averages.

24. The method of clause 23, wherein each sampling phase includes voltage measurements of fluoresced light from a plurality of light pulses emitted by a light source.

25. The method of clause 24, further comprising: obtaining a plurality of voltage measurements from each light pulse.

26. The method of clause 25, wherein the plurality of voltage measurements from each light pulse includes a first set of voltage measurements when the light source is turned on, and a second set of voltage measurements when the light source is turned off.

27. The method of clause 26, further comprising: calculating an average of the first set of voltage measurements; calculating an average of the second set of voltage measurements; and determining a light pulse differential value for each light pulse by subtracting the average of the second set of voltage measurements from the average of the first set of voltage measurements.

28. The method of clause 27, further comprising: determining an average voltage value for each sampling phase by calculating an average of the light pulse differential values of the plurality of light pulses in each sampling phase.

29. The method of clause 28, further comprising: determining a first polarization value for the first set of measurements of the sampling phase by calculating an average of the average voltage values of the first set of measurements of the sampling phase.

30. The method of clause 29, further comprising: determining a second polarization value for the second set of measurements of the sampling phase by calculating an average of the average voltage values of the second set of measurements of the sampling phase.

31. The method of clause 30, further comprising: determining a concentration value by subtracting the second voltage value from the first voltage value, and dividing by the sum of the first and second voltage values.

32. The method of clause 23, wherein the antibody is Immunoglobulin G (IgG).

33. A fluorescence polarization system for measuring a concentration of antibody protein in a cell sample, the system comprising: a processing circuitry having a memory for storing instructions which, when executed by the processing circuitry, cause the processing circuitry to: perform a measurement cycle of light fluoresced from the cell sample, the measurement cycle including the following order of measurements:

(2) measuring a second sampling phase of light fluoresced in a second direction before the midpoint of the measurement cycle, the second direction being perpendicular to the first direction:

(4) measuring a fourth sampling phase of the light fluoresced in the first direction after the midpoint of the measurement cycle; calculate a first average of the first and fourth sampling phases; calculate a second average of the second and third sampling phases; and determine the concentration of the antibody based on a function of the first and second averages.

34. The system of clause 33, wherein each sampling phase includes voltage measurements of fluoresced light from a plurality of light pulses emitted by a light source. 35. The system of clause 34. wherein the instructions, when executed by the processing circuitry, further cause the processing circuitry to: obtain a plurality of voltage measurements from each light pulse.

36. The system of clause 35. wherein the plurality of voltage measurements from each light pulse includes a first set of voltage measurements when the light source is turned on, and a second set of voltage measurements when the light source is turned off.

37. The system of clause 36. wherein the instructions, when executed by the processing circuitry, further cause the processing circuitry to: calculate an average of the first set of voltage measurements; calculate an average of the second set of voltage measurements; and determine a light pulse differential value for each light pulse by subtracting the average of the second set of voltage measurements from the average of the first set of voltage measurements.

38. The system of clause 37, wherein the instructions, when executed by the processing circuitry, further cause the processing circuitry to: determine a voltage value for each sampling phase by calculating an average of the light pulse differential values of the plurality of light pulses in each sampling phase.

39. The system of clause 38, wherein the instructions, when executed by the processing circuitry, further cause the processing circuitry to: determine a first polarization value by calculating an average of the voltage values for each sampling phase of the light fluoresced in the first direction.

40. The system of clause 39. wherein the instructions, when executed by the processing circuitry, further cause the processing circuitry to: determine a second polarization value by calculating an average of the voltage values for each sampling phase of the light fluoresced in the second direction. 41. The system of clause 40, wherein the instructions, when executed by the processing circuitry, further cause the processing circuitry to: determine the concentration of the antibody by subtracting the second polarization value from the first polarization value, and dividing by a sum of the first and second polarization values.

42. The system of clause 33. wherein the antibody is Immunoglobulin G (IgG).

43. A fluorescence polarization system for measuring a concentration of Immunoglobulin G (IgG) in a sample, the system comprising: a processing circuitry having a memory for storing instructions which, when executed by the processing circuitry, cause the processing circuitry to: perform a measurement cycle measuring a first set of sampling phases of light fluoresced in a first direction and a second set of sampling phases of the light fluoresced in a second direction, the second direction being substantially perpendicular to the first direction, at least one sampling phase of the light fluoresced in the second direction occurring between sampling phases of the light fluoresced in the first direction, each sampling phase in the first and second sets of sampling phases including voltage measurements of the light from a plurality of light pulses emitted by a light source; obtain a plurality of voltage measurements from each light pulse, wherein the plurality of voltage measurements from each light pulse includes a first set of voltage measurements when the light source is turned on, and a second set of voltage measurements when the light source is turned off; calculate an average of the first set of voltage measurements; calculate an average of the second set of voltage measurements; determine a light pulse differential value for each light pulse bysubtracting the average of the second set of voltage measurements from the average of the first set of voltage measurements; determine a voltage value for each sampling phase by calculating an average of the light pulse differential values of the plurality of light pulses in each sampling phase; determine a first polarization value for the first set of sampling phases by calculating an average of the voltage values in the first set of sampling phases; determine a second polarization value for the second set of sampling phases by calculating an average of the voltage values for the second set of sampling phases; and determine a concentration value of the IgG by subtracting the second polarization value from the first polarization value, and dividing by a sum of the first and second polarization values.

44. A cell analysis system for measuring a concentration of an antibody in a sample, the system comprising: a light source; an excitation polarizer polarizing light emitted from the light source in a first direction; a container configured to receive the light polarized in the first direction; a polarizer holder retaining first and second detection polarizers, the first detection polarizer restricting passage of light fluoresced from within the container to the first direction, and the second detection polarizer restricting the passage of the light fluoresced from within the container to a second direction, the second direction being perpendicular to the first direction; a detector for measuring the light fluoresced in the first direction and the light fluoresced in the second direction; and processing circuitry having a memory for storing instructions which, when executed by the processing circuitry, cause the processing circuitry to: rotate the polarizer holder about an axis of rotation in alternating directions causing alternate placement of the first and second detection polarizers in an optical path of the light fluoresced from within the container.

45. The system of clause 44, wherein the instructions, when executed by the processing circuitry, further cause the processing circuitry to: rotate the polarizer holder to position the first detection polarizer in the optical path of the light fluoresced from within the container; and rotate the polarizer holder to position the second detection polarizer in the optical path of the light fluoresced from within the container.

46. The system of clause 44, further comprising: an optics plate having a groove that terminates into first and second stops; and wherein the polarizer holder includes a pin that displaces inside the groove of the optics plate as the polarizer holder rotates about the axis of rotation.

47. The system of clause 46, wherein the optics plate further includes a first magnet positioned next to the first stop and a second magnet positioned next to the second stop of the groove; and wherein the pin is made of a ferromagnetic material that is attracted by the first magnet when positioned next to the first stop at the end of a first rotational travel, and the pin is attracted to the second magnet when positioned next to the second stop at the end of a second rotational travel.

48. The system of clause 46, wherein the groove is curved along the axis of rotation.

49. The system of clause 44. wherein the polarizer holder includes a first side surface, and a second side surface that is perpendicular to the first side surface, the first side surface including a first recessed portion for holding the first detection polarizer, and the second side surface including a second recessed portion for holding the second detection polarizer.

50. The system of clause 49, wherein the polarizer holder further includes a first biasing element attached to the first side surface to secure the first detection polarizer in the first recessed portion, and a second biasing element attached to the second side surface to secure the second detection polarizer in the second recessed portion.

51. The system of clause 50, wherein the first and second detection polarizers protrude beyond the first and second side surfaces when placed inside the first and second recessed portions, respectively, and the first and second biasing elements flex around the first and second detection polarizers to secure the first and second detection polarizers in place.

52. The system of clause 51, wherein the first and second biasing elements include cutouts to increase flexure around the first and second detection polarizers.

53. The system of clause 49. wherein the polarizer holder further includes a curved surface connecting the first and second side surfaces, the curved surface having apertures that align with apertures in the first and second recessed portions allowing the light fluoresced from within the container to pass through the polarizer holder and reach the detector.

54. The system of clause 53, further comprising: an optical cover that houses at least partially the detector and the polarizer holder, the optical cover including a curved wall that aligns with the curved surface of the polarizer holder to mitigate a space between the polarizer holder and the curved wall.

55. The system of clause 44. further comprising: a work platform; a liquid storage module mounted on the work platform, the liquid storage module including: a base having an interior volume for holding an internal reservoir: a primary lid connected to the base, the primary lid including a port providing access to the internal reservoir; a secondary lid attached to the primary lid, the secondary lid configured to seal the port on the primary lid; a second motor attached to the secondary’ lid; and a dispensing system configured to move a probe along three mutually perpendicular axes above the work platform; and wherein the instructions, when executed by the processing circuitry, further cause the processing circuitry to: operate the second motor to open the secondary lid allowing the probe of the dispensing system to be inserted through the port on the primary lid to reach a bottom of the internal reservoir to aspirate a liquid contained therein; and operate the second motor to close the secondary lid to seal the port on the primary lid when the probe is removed from the port.

56. A polarizer holder for a cell analysis system, the polarizer holder comprising: a first side surface; a second side surface perpendicular to the first side surface; a curved surface connecting the first and second side surfaces; a first detection polarizer coupled on the first side surface, the first detection polarizer restricting passage of light fluoresced to a first direction; and a second detection polarizer coupled on the second side surface, the second detection polarizer restricting passage of light fluoresced to a second direction; the polarizer holder being configured to rotate about an axis of rotation causing alternate placement of the first and second detection polarizers in an optical path of the light.

57. The polarizer holder of clause 56, further comprising: a first recessed portion in the first side surface, wherein the first detection polarizer is mounted in the first recessed portion; and a second recessed portion in the second side surface, wherein the second detection polarizer is mounted in the second recessed portion.

58. The polarizer holder of clause 57, further comprising: a first biasing element attached to the first side surface to secure the first detection polarizer in the first recessed portion; and a second biasing element attached to the second side surface to secure the second detection polarizer in the second recessed portion.

59. The polarizer holder of clause 58, wherein the first and second detection polarizers protrude beyond the first and second side surfaces when placed inside the first and second recessed portions, respectively, and the first and second biasing elements flex around the first and second detection polarizers to secure the first and second detection polarizers in place.

60. The polarizer holder of clause 59, wherein the first and second retaining springs include cutouts to increase flexure around the first and second detection polarizers.

61. A method of fluorescence polarization for measuring a concentration of an antibody in a sample, the method comprising: positioning a polarizer holder in a first position such that a first detection polarizer is placed in an optical path of light fluoresced from within a container holding a sample of antibody mixed with a fluorescence polarization assay; detecting the light fluoresced from within the container after the light passes through the first detection polarizer, the first detection polarizer restricting passage of the light fluoresced from within the container to a first direction; rotating the polarizer holder about an axis of rotation to position the polarizer holder in a second position such that a second detection polarizer is placed in the optical path of the light fluoresced from within the container, the second detection polarizer restricting passage of the light fluoresced from within the container to a second direction; and detecting the light fluoresced from within the container after the light passes through the second detection polarizer.

62. The method of clause 61, further comprising: rotating the polarizer holder about the axis of rotation to return the polarizer holder from the second position to the first position.

63. The method of clause 61, wherein the polarizer holder is rotated 90 degrees between the first and second positions.

64. The method of clause 61, further comprising: determining a concentration of the antibody based on detecting the light passing through the first and second detection polarizers. 65. A module for a cell analysis system, the module comprising: a base having an interior volume holding an internal reservoir; a primary lid connected to the base, the primary lid including a port providing access to the internal reservoir; a secondary’ lid attached to the primary’ lid, the secondary lid configured to seal the port on the primary’ lid; a motor attached to the secondary lid; and a processing circuitry' having a memory for storing instructions which, when executed by the processing circuitry, cause the processing circuitry to: operate the motor to open the secondary lid allowing a probe to be inserted through the port on the primary lid to reach a bottom of the internal reservoir; and operate the motor to close the secondary lid to seal the port on the primary’ lid when the probe is removed.

66. The module of clause 65, further comprising: a gasket that seals around the internal reservoir when the primary’ lid is closed.

67. The module of clause 65, further comprising: a gasket that seals the port on the primary lid when the secondary lid is closed.

68. The module of clause 65, wherein the secondary' lid includes a top portion that covers the port on the primary lid when the secondary lid is closed, and a hinge that extends from the top portion, wherein the hinge is connected to the motor.

69. The module of clause 65, wherein the secondary' lid includes at least of one of a magnet and a ferrous element that is attracted to a corresponding element on the primary lid to marntain the secondary lid in a closed state.

70. The module of clause 65, wherein the secondary' lid includes a plunger that is configured to be at least partially inserted into the port on the primary' lid.

Claims

What is claimed is:

1. A system for measuring a concentration of an antibody in a sample, the system comprising: a light source; an excitation polarizer polarizing light emitted from the light source in a first direction; a container configured to receive the light polarized in the first direction; a polarizer holder retaining first and second detection polarizers, the first detection polarizer restricting passage of light fluoresced from within the container to the first direction, and the second detection polarizer restricting the passage of the light fluoresced from within the container to a second direction, the second direction being perpendicular to the first direction; a detector for measuring the light fluoresced in the first direction and the light fluoresced in the second direction: and processing circuitry having a memory for storing instructions which, when executed by the processing circuitry, cause the processing circuitry to: rotate the polarizer holder about an axis of rotation in alternating directions causing alternate placement of the first and second detection polarizers in an optical path of the light fluoresced from within the container.

2. The system of claim 1, wherein the instructions, when executed by the processing circuitry, further cause the processing circuitry' to: rotate the polarizer holder to position the first detection polarizer in the optical path of the light fluoresced from within the container; and rotate the polarizer holder to position the second detection polarizer in the optical path of the light fluoresced from within the container.

3. The system of claim 1, further comprising: an optics plate having a groove that terminates into first and second stops; and wherein the polarizer holder includes a pin that displaces inside the groove of the optics plate as the polarizer holder rotates about the axis of rotation.

4. The system of claim 3, wherein the optics plate further includes a first magnet positioned next to the first stop and a second magnet positioned next to the second stop of the groove; and wherein the pin includes a ferromagnetic material attracted by the first magnet when positioned next to the first stop at the end of a first rotational travel, and the pin is attracted to the second magnet when positioned next to the second stop at the end of a second rotational travel.

5. The system of claim 3, wherein the groove is curved along the axis of rotation.

6. The system of claim 1, wherein the polarizer holder includes a first side surface, and a second side surface that is perpendicular to the first side surface, the first side surface including a first recessed portion for holding the first detection polarizer, and the second side surface including a second recessed portion for holding the second detection polarizer.

7. The system of claim 6, wherein the polarizer holder further includes a first biasing element attached to the first side surface to secure the first detection polarizer in the first recessed portion, and a second biasing element attached to the second side surface to secure the second detection polarizer in the second recessed portion.

8. The system of claim 7, wherein the first and second detection polarizers protrude beyond the first and second side surfaces when placed inside the first and second recessed portions, respectively, and the first and second biasing elements flex around the first and second detection polarizers to secure the first and second detection polarizers in place.

9. The system of claim 8, wherein the first and second biasing elements include cutouts to increase flexure around the first and second detection polarizers.

10. The system of claim 6, wherein the polarizer holder further includes a curved surface connecting the first and second side surfaces, the curved surface having apertures that align with apertures in the first and second recessed portions allowing the light fluoresced from within the container to pass through the polarizer holder and reach the detector.

11. The system of claim 10, further comprising: an optical cover that houses at least partially the detector and the polarizer holder, the optical cover including a curved wall that aligns with the curved surface of the polarizer holder to mitigate a space between the polarizer holder and the curved wall.

12. The system of claim 1. further comprising: a work platform; a liquid storage module mounted on the work platform, the liquid storage module including: a base having an interior volume for holding an internal reservoir; a primary lid connected to the base, the primary lid including a port providing access to the internal reservoir; a secondary lid attached to the primary lid, the secondary lid configured to seal the port on the primary⁷ lid; a second motor attached to the secondary lid; and a dispensing system configured to move a probe along three mutually perpendicular axes above the work platform; and wherein the instructions, when executed by the processing circuitry⁷, further cause the processing circuitry to: operate the second motor to open the secondary lid allowing the probe of the dispensing system to be inserted through the port on the primary lid to reach a bottom of the internal reservoir to aspirate a liquid contained therein; and operate the second motor to close the secondary lid to seal the port on the primary lid when the probe is removed from the port.

13. A polarizer holder for a cell analysis system, the polarizer holder comprising: a first side surface; a second side surface perpendicular to the first side surface; a curved surface connecting the first and second side surfaces; a first detection polarizer coupled on the first side surface, the first detection polarizer restricting passage of light fluoresced to a first direction; and a second detection polarizer coupled on the second side surface, the second detection polarizer restricting passage of light fluoresced to a second direction; the polarizer holder being configured to rotate about an axis of rotation causing alternate placement of the first and second detection polarizers in an optical path of the light.

14. The polarizer holder of claim 13, further comprising: a first recessed portion in the first side surface, wherein the first detection polarizer is mounted in the first recessed portion; and a second recessed portion in the second side surface, wherein the second detection polarizer is mounted in the second recessed portion.

15. The polarizer holder of claim 14, further comprising: a first biasing element attached to the first side surface to secure the first detection polarizer in the first recessed portion; and a second biasing element attached to the second side surface to secure the second detection polarizer in the second recessed portion.