WO1996001413A1 - A method for monitoring performance of an incubator module, said incubator module being comprised in an automated system for assaying multiple samples and a kit suitable for use in said method - Google Patents
A method for monitoring performance of an incubator module, said incubator module being comprised in an automated system for assaying multiple samples and a kit suitable for use in said method Download PDFInfo
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- WO1996001413A1 WO1996001413A1 PCT/EP1995/002535 EP9502535W WO9601413A1 WO 1996001413 A1 WO1996001413 A1 WO 1996001413A1 EP 9502535 W EP9502535 W EP 9502535W WO 9601413 A1 WO9601413 A1 WO 9601413A1
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- temperature
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- photometer
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
- G01K15/00—Testing or calibrating of thermometers
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01L—CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE
- B01L7/00—Heating or cooling apparatus; Heat insulating devices
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
- G01K11/00—Measuring temperature based upon physical or chemical changes not covered by groups G01K3/00, G01K5/00, G01K7/00 or G01K9/00
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
- G01K11/00—Measuring temperature based upon physical or chemical changes not covered by groups G01K3/00, G01K5/00, G01K7/00 or G01K9/00
- G01K11/12—Measuring temperature based upon physical or chemical changes not covered by groups G01K3/00, G01K5/00, G01K7/00 or G01K9/00 using changes in colour, translucency or reflectance
- G01K11/16—Measuring temperature based upon physical or chemical changes not covered by groups G01K3/00, G01K5/00, G01K7/00 or G01K9/00 using changes in colour, translucency or reflectance of organic materials
Definitions
- Automated systems for carrying out multiple assays are well known in the art. Such automated systems can incorporate a number of functions for processing assays; incubation, reagent addition, washing, absorbance measurement, shaking and sample transport. The latter implies that the automated system will basically execute complete assay procedures, without operator intervention, according to assay protocols present in the systems software. These assay protocols are, of course, based on the instructions in the test kit package inserts. In particular in the field of biotechnology and e.g. in the area of immunotechnology large numbers of samples are to be processed. In general in the field of biotechnology microplates are the preferred containers for carrying out reactions. Good Laboratory Practice (GLP), includes the periodic checking of laboratory instrumentation for proper functioning.
- GLP Good Laboratory Practice
- incubator modules For the majority of the functions of the automated systems for carrying out multiple assays, suitable means for checking their performance exist. An exception is formed by the incubator modules, said incubator modules being used to heat the samples e.g. present in microplates to a defined temperature and to maintain that temperature over a defined period of time.
- the means available entail indirect measurement of the temperature of the samples at the site of the incubator module.
- indirect measurement for example comprises measurement of the temperature of the heating elements of the incubator module which obviously is a very crude measurement of the actual sample temperature and does not take into account the fact that the module, the sample container and the samples themselves have to warm up to the temperature set for the incubator module. Neither does it enable an accurate analysis of temperature dispersion over a microplate.
- Another method comprises measurement of the temperature of the environment in which the microplate is present, but also has the same shortcomings with regard to warming up and temperature dispersion determination.
- Another alternative is to directly measure the temperature of a sample being incubated using a thermosensor immersed in the sample.
- thermosensors are often used in assays of biotechnological nature stems also from the interference with the incubation temperature and the assay itself due to the presence of the sensor itself.
- sample sizes are so small that heat transport through the metal sensor itself will influence the temperature of the sample. Thus even determination of the temperature in one sample present in a microplate could not be considered accurate.
- a performance check for an incubator comprised in an automated system for assaying multiple samples simultaneously at a defined temperature in particular suitable for asaying small samples requires a medium and means, compatible with the microplate format, that will allow quantification of the temperature and in particular the temperature distribution during incubation at the site of incubation.
- the method should have an accuracy better than 1 °C and a precision better than 0.1 °C.
- thermochromic properties would be most suitable as a solution as this would allow the photometer of an automated system for carrying out assays such as the Microplate Processor 3000 (MPP) to be used as a means of quantification linking absorbance to temperature.
- MPP Microplate Processor 3000
- An alternative was investigated; A buffer solution with a large acidity (pH) dependence on temperature (T) and an acid-base indicator with a large absorbance (A) dependence on acidity (pH). The result is what was aimed for: a solution of which the absorbance spectrum is temperature dependent.
- the subject invention is directed at a method for obtaining the desired accuracy and precision with regard to the actual temperature of a sample in an incubator in an automated assay system and even with regard to the temperature dispersion over a number of samples being simultaneously incubated.
- the invention is directed at obtaining this information in systems directed at automated processing of microplates.
- the subject invention has the additional advantages that not only the previous inadequacies regarding the technical aspects are overcome but that the solution is simple and relatively low in cost, simple to carry out and requires little adjustment to existing automated systems.
- the subject invention is directed at a method for monitoring performance of an incubator module said incubator module being suitable for incubating multiple samples simultaneously at a defined temperature (e.g. for incubating microtitre plates), said incubator module being comprised in an automated system for assaying multiple samples optionally in multiple simultaneous assays e.g. in multiple microtitre plates, said method comprising
- step 2) saving data of step 1) in a data file 3) measuring the absorbance of a temperature independent calibration solution for the two wavelengths ⁇ l and ⁇ 2 of step 1) in the photometer (phot 2), said temperature independent calibration solution exhibiting the same absorbance spectrum as the temperature dependent solution at the defined temperature, said measuring providing absorbance values and Ac a ⁇ . P hot 2x2.
- Acai >P hot 2./.1 indicates the absorbance (A) determined for the temperature independent calibration solution (cal), using the photometer (phot 2) at wavelength ⁇ l and 2
- ⁇ 2 indicates the absorbance (A) determined for the temperature independent calibration solution (cal), using the photometer (phot 2) at wavelength ⁇ 2 and 4) .
- a ⁇ Lphot ⁇ . ⁇ i indicates the absorbance (A) determined for the temperature independent calibration solution (cal), using the further photometer (phot 1) at wavelength ⁇ l and Ac a ⁇
- p h 0 t indicates the absorbance (A) determined for the temperature independent calibration solution (cal)
- thermochromic indicator solutions such as TRIS/Cresol Red in determining the temperature of a multicuvette photometer in combination with a thermically independent solution of Cresol Red in
- HEPES and phosphate buffer in a manner to eliminate errors of optical measurements caused by variations of pathlength and blank transmittance of the wells.
- a third wavelength was required to eliminate errors produced by different blank transmittances in addition to the quotient of two wavelengths to eliminate the errors due to different light path lengths or chromophore concentrations.
- the temperature independent buffer is used in the cited literature to simply study the influence of photometric noise on the accuracy and precision of the method and not for calibration purposes as in the subject method. No problem with regard to cooling down effect is present in the cited method as it is not directed at a process similar to the subject method. Simply carrying out the described method of Schilling et al in the subject situation will not solve the problem the subject method solves.
- the system allows determination of the temperatures of the liquid in the wells of a microplate e.g. while the microplate is in an incubator module of an automated assay system comprising the incubator module.
- a suitable example of a system in which the method according to the invention can be carried out is the Microplate Processor 3000.
- Tris(hydroxymethyl)-aminomethane (TRIS) in combination with hydrochloric acid (HC1) was selected as an extremely suitable example of a buffer system to be used in a method according to te invention.
- TIS Tris(hydroxymethyl)-aminomethane
- HC1 hydrochloric acid
- the buffer system of the temperature dependent solution has a large ⁇ pH/ ⁇ T, preferably at least an absolute value of 0,02 pH units /°C. The larger the absolute value the better any small change in temperature will register as a noticeable change in pH leading to a change in the absorbance which is measured, thereby increasing the sensitivity of the method.
- a temperature dependent solution exhibiting a large ⁇ A/ ⁇ pH value is preferred. Large can suitably be quantified as a value sufficient to result in at least a precision of 0,1 °C and an accuracy of at least 0,5 °C, preferably of at least 0,3 °C.
- a number of buffers other than TRIS are also suitable for use in a method according to the invention. Suitable examples comprise an aqueous solution selected from citrate, tartrate, phtalate, phosphate, tris(hydroxymethyl)aminomethane (also known commonly as TRIS), Borax and sodium bicarbonate.
- a number of acid-base indicators can be used in temperature dependent and temperature independent solutions for the subject method.
- Calibration solutions that have temperature independent spectra being identical to the spectra of the temperature dependent solution at certain temperatures offer some interesting possibilities. Firstly, such calibration solutions offer the possibility to experimentally determine the precision of the method. Secondly such calibration solutions offer the possibility to use different photometers for calibrating the method (determination of ⁇ ' and ⁇ ' using measured temperatures and absorbance values) and for actual temperature measurements (calculate T with known ' and ⁇ ' and measured absorbance values). Using a temperature independent calibration solution to compensate for the differences between photometers works as follows [4]:
- the temperature to be measured must have a certain expected value.
- a calibration solution must then be available that has a spectrum approximately identical to that of the temperature dependent solution at that expected temperature.
- the temperature dependent solution is calibrated ( ⁇ ' and ⁇ ' are determined) using photometer (phot 1).
- the absorbance values of the temperature independent calibration solution at the two wavelengths of interest are measured on photometer 1. (Ac a ⁇ . ph ot ⁇ , ⁇ i and Ac a ⁇ . phoU , ⁇ 2 )
- the second photometer is used to measure the absorbance values at the two wavelengths of interest of both the temperature dependent (At e st, P hot2, ⁇ i and A,est, P hot2, ⁇ 2) and temperature independent calibration solution and Ac a ⁇ . ph ot2, ⁇ 2)- Now the measurements of the temperature dependent solution from photometer 2 can be expressed in absorbance units of photometer 1, i.e. the corrected absorbance values, for both wavelengths: Acorr -" (Acal, p hou Acal, p hot 2 ) • At es t,phot2 (3)
- This method compensates for: - Small differences in blank media, e.g. water versus air.
- a microplate filled with the temperature dependent solution such as TRIS/Cresol Red solution cools down during the transport from the incubator module to the photometer (phot 2), (also referred to as the reader module in the following text) the obtained absorbance values do not accurately represent the temperatures as they were when the microplate was actually still in the incubator module. Therefore in a method according to he invention calculating means are used to correct the absorbance deteremined in the photometer (phot 2) with regard to the cooling down effect that occurs between the locations of incubation and absorbance measurement.
- a way to minimise the inaccuracy is to have the photometer as close to the incubator as possible and preferably in an atmosphere as close to the temperature ofthe incubator as possible.
- a way to overcome inaccuracy due to the transport is to registrate the cooling down curve for the sample in the container, preferably for each well of a microplate if a microplate is used and to use these curves to estimate the temperatures as they were in the incubator module.
- the subject invention is therefore also directed at a method as disclosed above, wherein a first microplate filled with temperature independent calibration solution is transported to the photometer (phot 2) and the absorbance is read at the two wavelengths ⁇ l and ⁇ 2, measurement data is saved in a data file and the microplate is taken to the output module to be removed, a second microplate comprising temperature dependent solution is taken to the incubator module and incubated at the defined temperature according to the setting of the incubator module and after completion of incubation is transported to the photometer (phot 2), where the absorbance is read a number of times at the two wavelengths ⁇ l and ⁇ 2 at time intervals preferably controlled by a software timer and all data is saved in a data file.
- the time interval between incubation termination and the first reading in the photometer (phot 2) is preferably as short as possible. It is limited by the time required for transport of the microplate from incubator module to the photometer (phot 2), said time interval preferably being less than 45 seconds, suitably being 25-35 seconds.
- a suitable embodiment of a method where the absorbance is read a number of times at the two wavelengths after the container with the temperature deependent solution has been removed from the incubator is a method wherein the time interval between absorbance measurements in the photometer (phot 2) is determined by the length of time required for the measurement of the absorbance at the two wavelengths ⁇ l and ⁇ 2 and the length of time required to save the data in a file, said time interval in general being longer than 25 seconds, preferably being less than 45 seconds and suitably being 30 seconds.
- the temperature determined on the basis of absorbance data from the photometer (phot 2) is corrected for the cooling down that occurs between transport from incubator module to said photometer calculating means on the basis of a mathematical function fitting the pattern of cooling down such that the regression coefficient R 2 is equal to or larger than 0.98 can suitably be used.
- the calculating means employed can for example enable a function for absorbance against time to be fitted in the least squares sense on the absorbance measurement data obtained in the photometer (phot 2) enabling calculation of actual absorbance in the incubator module at the moment of taking the temperature dependent solution from the incubator module i.e. at time zero thereby enabling subsequent calculation of the actual temperature in the incubator module at time zero.
- the temperature T of an object with an initial temperature T in i t that is placed in an environment with constant temperature T env as a function of time t is theoretically given by:
- T(t) T env + (Tini, - T en ) ⁇ e " ⁇ ( ⁇ is a time constant) (6)
- A(t) a + b . t + c . t 2 (+ d . t 3 ) (a, b, c and d are constants) (7)
- a is an estimate for the absorbance value at time zero.
- the temperature of sample in each well is influenced by neighbouring wells. The influence will vary with location of the well.
- data filtering can be applied in the calculations.
- the incubator modules of the automated assaying systems such as the Microplate
- Processor 3000 have low frequency characteristics, i.e. the temperature distribution over the microplate can show temperature gradients, cold areas, warm areas or an edge effect. Temperature values jumping up and down from well to well (high frequency behaviour) is not possible. This implicates that any high frequency components in the temperature distribution obtained by the method in this report, may be filtered out by means of a so-called "two dimensional low pass" filter.
- Many commonly used data filtering techniques are based on multiplication with an appropriate function in the frequency domain (with the Fourier transform of the signal) or taking the convolution of the signal with an appropriate function. These techniques require endless signals or at least signals that are defined over a relative large area.
- T filt D 6 fl ⁇ T C5 + f 2 . Tee + f 3 • Tc7 + t ⁇ . T D5 + fj . T D6 + + f 6 . T D7 + f7 . T E5 + f 8 . T E6 + f9. T E 7 (8)
- Tf is the calculated temperature after filtering and f ⁇ through f 9 are constants.
- the constants are calculated by fitting a linear model in the sense of the least squares to the temperature data of a square block of 9 wells, (two dimensional linear regression)
- T fllt A l fl.T A l + f 2 .TA2 + f 3 .T B l + f .TA3 + f 5 .T B2 +
- the subject invention is also directed at a test kit comprising components necessary for carrying out the invention as described above and in the Example.
- a test kit comprising at least a container comprising a temperature dependent solution exhibiting at least an absorbance higher than 0,5 AU at wavelengths ⁇ l and ⁇ 2 at the defined temperature, said temperature dependent solution comprising a buffer system with a temperature dependent pH and an acid- base indicator with an absorbance spectrum linked to pH and a container comprising at least one temperature independent calibration solution exhibiting an absorbance spectrum identical to that of the temperature dependent solution at the defined temperature, said temperature independent calibration solution preferably comprising a composition as close to that of the temperature dependent solution as possible.
- the solutions in such a kit have a pH a) in the working range of the buffer system of the temperature dependent solution at the defined temperature at which measurement is to take place, said defined temperature being within a desired temperature range, preferably being within the range 20-60 °C, b) in the indication range of the acid-base indicator at the defined temperature at which measurement is to take place, c) such that the absorbances at the two wavelengths ⁇ l and ⁇ 2 are as close to eachother as possible at a temperature in the middle ofthe specified range. d) preferably as low as possible to prevent CO2 absorption.
- the temperature dependent buffer can comprises an aqueous solution of citrate, tartrate, phtalate, phosphate, Tris(hydroxymethyl)aminomethane, Borax or sodium bicarbonate, preferably of Tris(hydroxymethyl)aminomethane.
- the temperature independent calibration solution can comprise HEPES, phosphate and a Cresol Red solution and is preferably further identical to the temperature dependent solution which comprises Tris(hydroxymethyl)- aminomethane as buffer and a Cresol Red solution as acid-base indicator.
- the solutions in the kit are preferably provided with anti microbial agents generally used inthe art such as azide.
- anti microbial agents generally used inthe art such as azide.
- cinnamaldehyde and gentamicin sulphate will be used with a view to regulations in particular countries.
- the Example provides further precise details ofthe solutions that can be present in a kit and an embodiment of how they can be used.
- a kit according to the invention will comprise the calibration data required using photometer (phot 1), thereby rendering the practical application extremely simple and userfriendly.
- the method and kit according to the invention in the various embodiments disclosed can be used to check the temperature dispersion of the incubator module at a number of different defined temperatures, said method or kit requiring a number of temperature independent calibration solutions equivalent to the number of different temperatures.
- an automated assay in an automated system can be carried out whilst the method according to the invention is carried out.
- the method according to the invention has been carried out using a Microplate Processor 3000 as automated assaying system comprising an incubator.
- the following reagents were used:
- Tris(hydroxymethyl)-aminomethane (TRIS) Tris(hydroxymethyl)-aminomethane (TRIS)
- Cresol Red is reported to be from pH 7.2 to pH 8.8 with a yellow to red colour transition [6]. This means that in the lower region of the visible spectrum the absorbance increases with increasing acidity (decrease of pH), whereas in the higher region ofthe visible spectrum the absorbance decreases with increasing acidity.
- a high concentration solution in ethanol was thought to be the most convenient dosage form for Cresol Red.
- a stock solution was prepared by dissolving Cresol Red (Kodak) in ethanol (Baker, 96%) in a concentration of 10.0 g/L.
- HEPES/phosphate solution For experimentally determining the precision of the method and for calibration purposes, the need was felt to have a solution with a temperature independent absorbance spectrum, but identical to that ofthe TRIS/Cresol Red solution at a certain temperature. As described in literature [2], such a solution can be prepared by replacing the TRIS in the TRIS/Cresol Red solution by a mixture of HEPES and phosphate.
- the TRIS/Cresol Red and calibration solutions have to be stable for quite some time.
- preservatives have to be added to prevent microbial degradation.
- sodium azide was not selected because of restrictions in some countries. Instead, cinnamaldehyde and gentamicin sulphate, as used in some components of the latest Organon Teknika Microelisa assays, was used.
- a stock solution of cinnamaldehyde was prepared by diluting cinnamaldehyde in 96% ethanol + 5% methanol (Baker) in a concentration of 200 ml/L.
- Cinnamaldehyde (Merck) and gentamicin sulphate (USBC) were added to the TRIS and HEPES/phosphate solutions up to final concentrations of 0.2 ml/L and 0.1 g/L respectively.
- TRIS/Cresol Red temperature dependent and temperature independent calibration solutions were prepared in the following manner:
- pH should be in the working range of TRIS buffer in the temperature range of interest. pH should be in the indication range of Cresol Red in the temperature range of interest. - pH should be as low as possible to minimize C0 2 absorption. pH setting should be such that in the middle of the temperature range of interest (at approx. 37 °C) the absorbances at the two wavelengths being used, are approximately equal.
- Cresol Red concentration should be such that the absorbance values at the two wavelengths being used, are in the range 0.5 - 1.5 AU (optimal working range of the reader module ofthe MPP) in the temperature range of interest.
- pH values correspond to the pH values of the TRIS/Cresol Red solution at 37 °C and 50 °C respectively.
- the two portions were each divided into two portions to which Cresol Red (stock solution) was added up to final concentrations of 30 mg/L and 75 mg/L respectively. It was verified that the addition of Cresol Red did have no measurable effect on the pH.
- Spectra were recorded in the visible region, 400 through 700 nm, using a Pye Unicam Model PU8700 spectrophotometer and polystyrene cuvettes (1 cm optical pathlength) with an internal width of approx. 1 cm.
- the double walled cell-holder of this instrument is connected to a temperature controlled waterbath via tubings and a pump.
- the temperature in the cuvette is measured by means of a thermocouple, positioned just above the lightbeam generated by the spectrophotometer.
- the thermocouple is connected to a Fluke Model 27 multimeter equipped with a Model 80TK Thermocouple Module.
- the amount of fluid in the cuvette is such that the insertion depth ofthe thermocouple is approx. 3 mm.
- Spectra for the calibration solutions were recorded at room temperature and saved in data files for further processing. Just before every measurement, the spectrophotometer was blanked against a cuvette containing water.
- Spectra for the TRIS/Cresol Red solutions were recorded in the range room temperature to 52 °C. For practical reasons, spectra were recorded during warming up or cooling down of the liquid in the cuvettes, instead of stabilizing the temperature in the cuvette for every measurement. Heating of the waterbath was set in such a way that a temperature raise of approx. 1 °C per 6 minutes in the cuvette was achieved. By doing so, the error of the measured temperature because ofthe fact that it takes a certain time to record a spectrum (approx. 20 sec), is less than 0.1 °C. The measurement accuracy of the thermocouple system is 0.1 °C. Spectra were recorded at approx. 2 °C intervals and saved in data files for further processing. For each recorded spectrum, the temperature of the fluid in the cuvette was noted. Just before every measurement the spectrophotometer was blanked against a cuvette containing water.
- Cooling ofthe waterbath is achieved by heat conduction to a coiled tube positioned in the waterbath through which (cold) tap water runs.
- the flow of tap water was set in such a way to achieve a temperature drop of approximately 1 °C per 6 minutes. Spectra were recorded in a similar way as during heating up.
- the used MPP was one of the 5 prototypes con Figured with prototype software, i.e. created with Turbo C and running under MS-DOS.
- two protocols were programmed for the MPP that essentially only differ for the incubation temperature, i.e. one protocol for 37 °C incubation and one for 50 °C incubation.
- 37 °C and 50 °C are the two incubation temperatures at which the incubator modules of the MPP are to be tested for accuracy and temperature distribution over the microplate.
- the first microplate filled with calibration fluid(s) is transported to the reader module and is read at two wavelengths (endpoint readings). Measurement data is saved in data files and the microplate is taken to the output module for removal by the operator.
- the second microplate is taken to the reader module and is read at two wavelengths (endpoint readings). These readings are related to the temperature outside the MPP and the temperature inside the instrument.
- microplate was then taken to the incubator module #3 and incubated for 20 minutes at 37 °C setpoint or for 40 minutes at 50 °C setpoint.
- the microplate was taken to the reader module where the plate was read 10 times at two wavelengths at time intervals controlled by a software timer. Time zero was defined as the moment the microplate was picked up by the transport module from the incubator plate carriage. Exact measurement times for the first wavelength are 30, 60, 90, 120, 150, 180, 210, 240, 270 and 300 sec. For the second wavelength these times are 35, 65, 95, 125, 155, 185, 215, 245, 275 and 305 sec. All measurement data was saved in data files for further processing. - After completion of all measurements, the microplate was taken to the output module for removal by the operator.
- the time interval of 30 sec. was chosen because it takes approx. this time to transport a microplate from an incubator module to the reader module.
- the time needed by the reader module to read at two wavelengths and to save the measurement data in a data file takes approximately 30 sec. as well.
- the accuracy of the method is defined as the error in the calculated average temperature versus the actual average temperature ofthe fluid in the wells of the microplate in the incubator module. Precision is defined as the obtained variation in successive determinations of the temperature.
- the accuracy depends mainly on the following: The accuracy at which ⁇ ' and ⁇ ' are determined.
- the variance of the calculated temperature can be calculated according to:
- Var(T) [Var(ln(A 5 4o/A 405 )) + Var( ⁇ ") + T 2 .Var( ⁇ ') + 2.T.Cov( ⁇ ", ⁇ ')]/ ⁇ ' 2 (14)
- Var(ln(A 54 o/A405)) in equation (14) may be neglected.
- Var( ⁇ ") will be equal to Var( ⁇ ')
- Cov( ⁇ ", ⁇ ') will be equal to Cov( ', ⁇ ').
- Equation (14) then reduces to:
- equation (15) for determining the accuracy of the method gives standard errors in the range 0.3 - 0.4 °C dependant on the temperature. Standard errors are 0.31 °C at 20 °C, 0.37 °C at 37 °C and 0.43 °C at 50 °C.
- the method is easy to perform. Especially when integrated in a commercial product, including the availability of processing and calculation routines in the Microplate Processor
- Figure 1A B Spatial low pass filtering by means of two dimensional linear regression.
- Figure 2. pH - temperature relation of 0.1 mol/L TRIS buffer.
- Figure 3. Absorbance spectra of TRIS/Cresol Red solution at various temperatures.
- Figure 4. Wavelength dependency of ⁇ and ⁇ .
- Figure 5. L ⁇ As ⁇ o/ ⁇ os) as a function ofthe temperature for the TRIS/Cresol Red solution.
- Figure 6. Absorbance as a function ofthe time for 37 °C incubation.
- Figure 7. Absorbance as a function ofthe time for 50 °C incubation.
- Figure 8. Temperature distribution of experiment 1 without spatial low pass filtering.
- Figure 9. Temperature distribution of experiment 1 with spatial low pass filtering.
- Figure 10. Temperature distribution of experiment 2 with spatial low pass filtering.
- Figure 11. Temperature distribution of experiment 3 with spatial low pass filtering.
- Figure 12. Temperature distribution of experiment 4 with spatial low pass filtering.
- n 9 540 nm 405 nm 540/405
- n 6 540 nm 405 nm 540/405
- n 48 without with spatial without with without with without with spatial without with spatial low low pass spatial spatial spatial spatial low pass spatial spatial pass filtering low pass low pass low pass low pass filtering low pass low pas filtering filtering filtering pass filtering filtering filterin filtering
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Abstract
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Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP8503667A JPH10502451A (en) | 1994-07-01 | 1995-06-29 | Method for monitoring the performance of an incubator module included in an automated system for assaying a large number of samples and kits suitable for use in this method |
EP95924952A EP0769137A1 (en) | 1994-07-01 | 1995-06-29 | A method for monitoring performance of an incubator module, said incubator module being comprised in an automated system for assaying multiple samples and a kit suitable for use in said method |
AU29258/95A AU685301B2 (en) | 1994-07-01 | 1995-06-29 | A method for monitoring performance of an incubator module, said incubator module being comprised in an automated systemfor assaying multiple samples and a kit suitable for use in said method |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
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EP94201918 | 1994-07-01 | ||
EP94201918.3 | 1994-07-01 |
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WO1996001413A1 true WO1996001413A1 (en) | 1996-01-18 |
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PCT/EP1995/002535 WO1996001413A1 (en) | 1994-07-01 | 1995-06-29 | A method for monitoring performance of an incubator module, said incubator module being comprised in an automated system for assaying multiple samples and a kit suitable for use in said method |
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EP (1) | EP0769137A1 (en) |
JP (1) | JPH10502451A (en) |
AU (1) | AU685301B2 (en) |
CA (1) | CA2194232A1 (en) |
WO (1) | WO1996001413A1 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
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NL1011738C2 (en) * | 1999-04-06 | 2000-10-09 | Sopachem B V | Calibration device for e.g. spectrophotometric devices, contains at least one calibration solution and can be repeatedly placed inside and taken out of measuring device |
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ES2348126T3 (en) * | 2007-02-01 | 2010-11-30 | Immundiagnostik Ag | DIRECT DETERMINATION OF VITAMIN D IN SERUM OR PLASMA. |
DE102008006245A1 (en) * | 2008-01-25 | 2009-07-30 | Nirlus Engineering Ag | Method for the noninvasive, optical determination of the temperature of a medium |
JP6497040B2 (en) * | 2014-11-21 | 2019-04-10 | 三浦工業株式会社 | Silica concentration measuring device |
JP6631867B2 (en) * | 2015-02-06 | 2020-01-15 | パナソニックIpマネジメント株式会社 | Method for measuring temperature of liquid in microchannel |
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1995
- 1995-06-29 JP JP8503667A patent/JPH10502451A/en active Pending
- 1995-06-29 EP EP95924952A patent/EP0769137A1/en not_active Ceased
- 1995-06-29 AU AU29258/95A patent/AU685301B2/en not_active Ceased
- 1995-06-29 CA CA 2194232 patent/CA2194232A1/en not_active Abandoned
- 1995-06-29 WO PCT/EP1995/002535 patent/WO1996001413A1/en not_active Application Discontinuation
Non-Patent Citations (2)
Title |
---|
BOWIE L. E.A.: "DEVELOPMENT OF AN AQUEOUS TEMPERATURE-INDICATING TECHNIQUE AND ITS APPLICATION TO CLINICAL LABORATORY INSTRUMENTATION", CLINICAL CHEMISTRY, vol. 22, no. 4, WINSTON US, pages 449 - 455 * |
SCHILLING K. E.A.: "MULTIWAVELENGTH PHOTOMETRY OF THERMOCHROMIC INDICATOR SOLUTIONS FOR TEMPERATURE DETERMINATION IN MULTICUVETTES", CLINICAL CHEMISTRY, vol. 39, no. 2, WINSTON US, pages 251 - 256 * |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
NL1011738C2 (en) * | 1999-04-06 | 2000-10-09 | Sopachem B V | Calibration device for e.g. spectrophotometric devices, contains at least one calibration solution and can be repeatedly placed inside and taken out of measuring device |
Also Published As
Publication number | Publication date |
---|---|
AU685301B2 (en) | 1998-01-15 |
CA2194232A1 (en) | 1996-01-18 |
JPH10502451A (en) | 1998-03-03 |
AU2925895A (en) | 1996-01-25 |
EP0769137A1 (en) | 1997-04-23 |
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