EP4042145A1

EP4042145A1 - Method and device for determining the condition of cells in reactors

Info

Publication number: EP4042145A1
Application number: EP20789046.8A
Authority: EP
Inventors: Konrad Herzog; David Frank
Original assignee: Aquila Biolabs GmbH
Current assignee: Aquila Biolabs GmbH
Priority date: 2019-10-07
Filing date: 2020-10-06
Publication date: 2022-08-17
Also published as: US20240053269A1; WO2021069428A1; DE102019006971A1

Abstract

The invention relates to a method for determining the condition of cells (1) in reactors (3) and to a device for carrying out the method. The invention can be used in particular to assess the viability and degree of contamination of cell suspensions. The invention can advantageously be used in mammal cell culture and other cultivation or fermentation processes in which the proportion of living cells in the total cell concentration changes during cultivation or which have a particular risk of contamination. In the described method, at least one ambient condition of a luminescent dye (5) in a reactor (3) is influenced by at least one condition of the cells (1), wherein: polarised light (7) from at least one light source (6) is radiated into a medium (2) cultivated in the reactor (3) and excites the at least one luminescent dye (5) to luminescence; at least some of the light (8) emitted by at least one luminescent dye (5) exits the medium (2) and is polarised by at least one polariser (9); the polarised emitted light (10) thus obtained is sensed by at least one light sensor (11); the polarised emitted light (10) is sensed at at least two different polarisation angles as at least two luminescence values (12.1, 12.2); and at least one anisotropy value (14) is determined from the at least two luminescence values (12.1, 12.2) by means of suitable mathematical methods (13), said anisotropy value correlating with at least one condition of the cells (1).

Description

Method and device for determining the condition of cells in

Reactors

description

Technical area

The invention relates to a method for determining the condition of cells in reactors and a device for carrying out the method. It is particularly applicable to assess the viability and the degree of contamination of cell suspensions. The invention is advantageously used in mammalian cell culture and other cultivation or fermentation processes in which the proportion of living cells in the total cell concentration changes in the course of the cultivation or which have a particular risk of contamination. The invention can also be used to assess further state parameters of cells, for example to characterize the metabolism.

The cultivation of cells in reactors is a fundamental process in many areas of the chemical, biological, biotechnological and pharmaceutical industry and research. Cells are cultivated in a nutrient medium under defined conditions, the nutrient medium with the cells being in a reactor. To monitor and control such bioprocesses, various parameters are collected, such as cell density, oxygen concentration, pH, temperature, and many more. In order to ensure an optimal yield and a constant quality of the bioprocess, further parameters that describe the condition of the cultivated cells often have to be collected, especially but not exclusively in the field of mammalian cell culture. In particular, it is monitored how high the proportion of living cells in the total number of cells is (viability) and whether the culture is contaminated or infected with undesired cells.

While process parameters such as cell density, oxygen concentration, pH or temperature can already be recorded automatically inline or online at the reactor, The determination of the condition of the cells usually requires the complex and time-consuming extraction of samples with subsequent manual evaluation, which disadvantageously results in a low data density and thus a poorer monitoring quality and an increased risk of contamination.

State of the art

A wide variety of methods and devices for determining the condition of cells which process or otherwise use or analyze samples which have been drawn from a reactor are known to the person skilled in the art. Such methods are, for example, microscopic methods for cell counting and classification, staining methods with subsequent evaluation in the microscope or cell counter, enzymatic or immunological assays, genomic or proteomic investigations and methods of flow cytometry. All these methods have the disadvantage that they require a sample to be taken from the cell suspension in the reactor, which is expensive and poses a risk of contamination.

Methods are also known which optimize the above-mentioned methods via a sample loop or an immersion probe through which there is a flow in such a way that sampling is no longer necessary. Known methods are, for example, in-situ microscopy or at-line flow cytometers. However, since the measuring devices used are comparatively large (mostly larger than 1000 cm ³ ), these methods can only be used meaningfully for correspondingly large-volume reactors. This has the disadvantage that for the smaller reactors used particularly frequently, such as shake flasks, shake flasks, microtiter plates, culture tubes or mini and microbioreactors, there is no possibility of determining the condition of cells without sampling. This is particularly disadvantageous because these smaller reactors can be highly parallelized and are therefore used in the field of process development, where high data densities are of particular importance.

The methods of impedance spectroscopy are also known. The cells are exposed to an alternating electric field of different frequencies by means of electrodes in contact with the culture liquid. Because intact cells as a result of their Cell membrane are polarizable depending on size and frequency, a distinction can thus be made between living and dead cells, so that only the number of living cells is determined. However, these methods disadvantageously require direct electrical contact between the electrodes and the culture liquid, so that the former have to be designed either as invasive immersion probes or as probes integrated into the reactor wall, so that the reactors usually used can no longer be used. In addition to the number of living cells, the impedance spectroscopy known from the prior art does not allow any further statements about the condition of the cultivated cells, for example with regard to contamination or metabolism.

Thus, no methods and devices are known which are suitable for determining the state of cells in reactors without direct contact with the culture liquid and without the need to take samples and which are at the same time highly miniaturizable and parallelizable so that they can be used in all common reactors, regardless of size can.

Task

It is therefore the object of the present invention to provide a method by means of which at least one state of cells in reactors can be determined without taking samples, without there being direct contact between the culture liquid and a sensor, with at the same time high parallelizability and miniaturizability of the methods and devices to be used compared to the prior art. The object on which the invention is based is achieved by a method according to claim 1 and a device for carrying out the method according to claim 7; preferred refinements result from the subclaims and the description.

Definitions

To ensure the clarity of some terms used in the description, these are defined and explained below and in the course of the description. For the purposes of the invention, cells are all (mostly by membranes) delimited biological or chemical systems that have the characteristics of life, which are characterized in particular, but not exclusively, by the ability to multiply or cell division and the ability to operate metabolism and energy exchange. Cells within the meaning of the invention are therefore in particular, but not exclusively, all eukaryotes and prokaryotes (bacteria and archaea), artificial or synthetically produced cells, as well as delimited systems that have emerged from at least one of the aforementioned cells. Cells have cell structures at various levels of molecular or macromolecular organization. A cell structure within the meaning of the invention is any component of a cell that differs from at least one other component of the cell due to its function, composition, shape, structure, localization or temporal and spatial presence. Cell structures within the meaning of the invention are in particular but not exclusively biomolecules (carbohydrates, proteins, peptides, amino acids, lipids, nucleic acids) and their complexes as well as cell organelles and compartments (e.g. mitochondria, nucleus, endoplasmic reticulum, Golgi apparatus, vesicles, lysosomes, vacuoles, Endosomes, exosomes, chloroplasts, membranes, cell walls, cytoskeleton, cytoplasm, etc.). Cell structures within the meaning of the invention can also be other physical, chemical or biological structures, provided they are located within the outermost extent of the cell, in particular but not exclusively phagocytosed particles or cell structures, other cells, viruses, phages, mycoplasmas and many more.

All properties of cells define states of cells, the determination of which is part of the object of the present invention. A state of cells within the meaning of the invention describes at least one property, the state parameter, of at least one cell at at least one point in time, wherein each state parameter must be able to assume at least two different values. Examples of states of cells are in particular, but not exclusively, the growth phase, the cell cycle phase, liveliness or viability, health, freedom from infection, metabolic activity, membrane integrity, size, shape, productivity, age, differentiation, the Proteome, gene activity, etc., with each cell having a variety of states at any point in time. A variety of the states of the invention includes several properties of the cell. Since the properties of the cell and thus its conditions are defined by the structure, shape, chemical composition, location, activity and much more. of the cell components or cell structures, conclusions can be drawn about the states defined by them through the interaction of luminescent dyes with these cell structures. For the purposes of the invention, however, states of cells can not only be described individually for each cell, but also as sums or other mixed states for populations of cells or the entirety of all cells in a medium or reactor. In the field of application of the present invention, the determination of such total states is often of great importance in order to be able to assess the quality and integrity of a cultivation of cells. For example, the viability of a culture describes the proportion of living cells in the total number of cells in the medium. According to the invention, sum or mixed states can also be defined for almost every individual state of a cell, which are in particular but not exclusively based on ratios (e.g. viability in percent) or through distributions (e.g. size distribution) with associated distribution parameters (e.g. expected value, variance, skewness, distribution function , etc.) can be described.

A medium within the meaning of the invention is a mixture of materials that functions as a carrier for the cells when processes are carried out with cells (e.g. cultivation, expression, storage, transport). Media within the meaning of the invention are often fluids and can contain, inter alia, nutrients, growth factors, trace elements, luminescent dyes and buffers. Media are often mixed in the process in order to maintain the distribution of their ingredients evenly. Media within the meaning of the invention are in particular, but not exclusively, all types of growth, differentiation and expression media for the cultivation of cells and storage fluids.

A reactor within the meaning of the invention is any container that can be filled with cells or cell-containing mixtures or media and can be used in particular, but not exclusively, for culturing, storing, working up, separating or transporting cells. Reactors within the meaning of the invention are in particular stirred tank fermenters, bubble column fermenters, shake flasks, T-flasks, microtiter plates, deep-well plates, shaking barrels, fermentation bags, Multipurpose tubes, serum bottles and tissue culture dishes. Reactors can be closed or open to their environment. For the purposes of the invention, reactors are distinguished by the fact that light can be radiated into them. For this purpose, reactors according to the invention can have partially or completely transparent walls (with transparency in particular in the wavelength range of the light used to carry out the method according to the invention), wall sections, windows, ports, probes or fiber connections.

A contamination within the meaning of the invention is a substance, a structure, a cell or a particle (e.g. viruses, phages, mycoplasmas, other bacteria, prions) that influences the behavior or various states of a cell in such a way that the cell moves in the presence of the Contamination behaves differently, and mostly undesirably differently, than in the absence of contamination.

Luminescent dyes within the meaning of the invention are all substances, ions, molecules, macromolecules or their complexes that show luminescence, which can therefore be put into an excited state by at least one photon depending on their electronic structure and at least this excited state with emission over a certain lifetime of a photon again. Luminescent dyes in the context of the invention are in particular fluorescent dyes and phosphorus dyes. The luminescence of luminescent dyes is dependent on their environment and can be changed by the interaction of the luminescent dye with the environment, in particular but not exclusively with regard to the excitation and emission spectra, the lifetime of the excited state and the polarization or polarization rotation of the emitted light. Luminescent dyes according to the invention show, depending on the luminescence lifetime and the interaction with their surroundings, a luminescence anisotropy, which in particular, but not exclusively, describes how strongly the emitted light is depolarized after excitation of a luminescent dye with polarized light. The higher the depolarization of the emitted light, the lower the luminescence anisotropy and the higher the polarization of the emitted light, the higher the luminescence anisotropy. The luminescence is recorded by suitable light sensors. In the context of the invention, luminescence values can in particular, but not exclusively, be based on static intensity measurements or by means of time-resolved methods in the frequency or time domain. The methods and modulation techniques required for this are known to the person skilled in the art.

Any device that is suitable for irradiating light into the reactor and / or the medium counts as a light source. In the context of the invention, light sources are particularly, but not exclusively, LEDs, OLEDs, lasers, incandescent lamps, fluorescent tubes, flash tubes and combinations of these light sources with at least one fluorescent layer. For the purposes of the invention, light sources can contain a variable or fixed polarizer for generating polarized light, can be combined with an external variable or fixed polarizer, or they can produce polarized light themselves. Light sources within the meaning of the invention can cover only one wavelength or a narrow wavelength range (laser, LED, OLED), or have a broad wavelength range. Since a narrow wavelength range is often advantageous for luminescence detection, light sources can contain wavelength-selective optical elements such as band-bass or edge filters, other filters, monochromators, prisms or diffraction gratings or can be combined with such optical elements. Light sources have a field of view which corresponds to the illuminated volume in general, but in particular to the illuminated volume of the medium in the reactor. Light sources can be combined with various optical elements to modify the field of view in the medium.

In the context of the invention, the wavelength of light describes both defined wavelength lines and wavelength ranges with at least one, but mostly two limits. Examples of the use of the term wavelengths in the context of the invention are “lasers with a wavelength of 532 nm” or “excitation wavelengths smaller than emission wavelengths”, the latter also being able to correspond to several wavelength ranges. The wavelength is abbreviated in the figures with the Greek letter lambda.

A polarizer within the meaning of the invention is any device that is suitable for polarizing light or for transmitting or reflecting only a certain part of the light with certain properties with regard to polarization. Polarizers in the sense According to the invention, individual polarizing elements or arrangements of several polarizing elements with the same or different polarization directions can be.

The polarization angle within the meaning of the invention is the angle between the polarization of the polarized exciting light and the polarization of the polarized emitted light or polarized scattered light.

A light sensor within the meaning of the invention is any device that is suitable for detecting light by generating at least one property of the detected light (in particular the intensity) an electrical reaction of the sensor (e.g. change in an electrical voltage, an electrical potential, an electrical current ), which is recognized, read out, further processed, converted or stored by other electronic components (e.g. analog-digital converters, operational amplifiers, comparators, resistors, capacitors, processors, computers, etc.) that may be part of the light sensor or downstream of it can be and ultimately recorded the detected property of the light as at least one value. A light sensor thus records a direct or processed or modified image of the electrical reaction of the sensor at a specific time. Light sensors within the meaning of the invention include, in particular, but not exclusively, photodiodes, photoresistors and phototransistors present individually or as an array or other combination of individual sensors, as well as 1 D-CCD chips (line sensors), 2D CCD chips, 1 D-CMOS-APS Chips (line sensors), 2D CMOS chips, photomultiplier tubes, silicon photomultipliers, avalanche photodiodes and light sensors with a fluorescent coating (e.g. for UV detection). The above-mentioned electronic components of light sensors can be partially divided between several sensors, for example via suitable multiplexers. Light sensors can contain polarizers or wavelength-selective optics, or be combined with them. Similar to light sources, light sensors also have a field of view and can be combined with various optical elements in order to modify the field of view in the medium or reactor.

Wavelength-selective optics within the meaning of the invention are all those optical elements which prefer, prevent or deflect the propagation, in particular transmission, reflection and diffraction, of light of a certain wavelength. Wavelength-selective optics within the meaning of the invention are in particular, but not exclusively, filters (edge, notch, bandpass, shortpass, longpass filters), prisms, optical gratings and slits and monochromators.

Mathematical methods in the sense of the invention are all methods that are suitable for analyzing, processing, combining to new values or drawing conclusions from data and measured values that have been recorded or calculated or derived using the method according to the invention. Mathematical methods within the meaning of the invention are in particular, but not exclusively, methods of statistics, regression analysis, optimization and compensation calculation, machine learning and evolutionary algorithms and neural networks.

An anisotropy value in the context of the invention is any value or any combination or series of values which describes the luminescence anisotropy of at least one luminescent dye at a specific point in time or in a specific period of time.

A computer within the meaning of the invention is any device that can store data (in particular arithmetic and logical) and process it on the basis of programmable rules. Computers within the meaning of the invention are in particular, but not exclusively, microcontrollers, microprocessors, FPGAs, system-on-a-chip computers (SoC), PCs and servers.

solution

According to the invention, the object is achieved by a method for determining the condition of cells in reactors, which uses the effect of luminescence anisotropy in order to be implemented as an optical method without direct contact with the culture liquid and with a high potential for minimization and parallelization.

The task is solved by a method for determining the state of cells that are cultivated in a medium which is located in a reactor, with at least one luminescent dye being located in the reactor, the luminescence anisotropy of which is dependent on its ambient conditions and with at least one ambient condition of the luminescent dye being influenced by at least one state of the cells . The solution to the problem according to the invention is thus based on the optical detection of the luminescence anisotropy of at least one luminescence dye as a measure of at least one state of the cells.

The method according to the invention is characterized in that polarized light is radiated into the medium from at least one light source and excites the at least one luminescent dye to luminescence and that the light emitted by at least one luminescent dye at least partially leaves the medium and is polarized by at least one polarizer. It is also characteristic that the polarized emitted light obtained in this way is detected by at least one light sensor and that the polarized emitted light is detected at at least two different polarization angles as at least two luminescence values, from which at least one anisotropy value is determined using suitable mathematical methods, which as a result of the Environment dependence of the luminescent dye correlates with at least one state of the cells.

The method according to the invention uses the dependence of the luminescence anisotropy of at least one luminescence dye on its ambient conditions. The luminescence anisotropy changes through a wide variety of physical processes, in particular but not exclusively through diffusion and rotation of the luminescent dye, through various types of radiation-free energy transfer (RET, FRET, etc.) or through radiation transfer and others, the electronic structure or the molecular mobility and rotation rate parameters influencing the luminescent dye (e.g. pH, shape, stability and size of the hydrate shell, viscosity of the solvent, temperature, pressure) and processes.

Luminescent dyes according to the invention for determining at least one state of cells are characterized in that their luminescence anisotropy can be influenced by at least one state of the cells. In this respect, the Can change ambient conditions of luminescent dyes according to the invention as a function of at least one state of the cells. This is achieved in particular, but not exclusively, through the cell state-dependent interaction of luminescent dyes according to the invention with at least one cell structure, such as cell compartments or cell components (proteins, polysaccharides, lipids, nucleic acids, etc. and their compounds, complexes or derived structures). However, this is also achieved through the cell-state-dependent interaction of luminescent dyes according to the invention with at least one structure that is not actually part of the cell, but is located within the cell or the medium and thus influences the state of the cells. Such structures, which are not part of the cell in the actual sense of the word, are in particular but not exclusively contaminations, bacteria, viruses, phages, prions, mycoplasmas, etc.

According to the invention, the interaction of the at least one cell structure with the at least one luminescent dye is dependent on at least one property of this cell structure, in particular but not exclusively on the presence, concentration, conformation, charge, size and location of the cell structure, as well as on their accessibility by the luminescent dye. According to the invention, depending on the state of the cells, differences arise with regard to at least one property of the cell structure interacting with at least one luminescent dye, so that the determined luminescent anisotropy relates to the interaction of at least one luminescent dye with at least one cell structure and from this to the at least one interaction property of the cell structure with the luminescent dye influencing the cell state can be closed.

In some embodiments of the invention, the cell state-dependent change in the luminescence anisotropy of at least one luminescent dye takes place through its binding to at least one cell structure or through its dissociation from at least one cell structure. According to the invention, in these embodiments, depending on the binding state of the luminescent dye, its mobility changes, in particular but not exclusively its diffusion or rotation rate, and thus its luminescence anisotropy. In some embodiments of the invention, the cell state-dependent change in the luminescence anisotropy of at least one luminescent dye takes place through its localization in or on at least one cell structure, with the localization (e.g. lysosome, vacuole, mitochondria, cell wall, cell nucleus, etc.) being associated with different environmental conditions, in particular but not exclusively with regard to pH, redox potential, charge, polarity, viscosity, ionic strength or solvent composition. According to the invention, in these embodiments, depending on the local environmental conditions of the luminescent dye, its mobility or electronic structure, and thus its luminescence anisotropy, change.

In some embodiments of the invention, the cell state-dependent change in the luminescence anisotropy of at least one luminescent dye takes place by energy transfer to suitable neighboring cell structures as acceptor molecules. This energy transfer can take place without radiation (RET / FRET) or with the emission of radiation. Since, in particular, radiation-free energy transfer depends on the distance between donor and acceptor, states of cells can be determined in such designs, the change of which is accompanied by a change in distance to at least one cell structure or between two cell structures or the disintegration of cell structures. According to the invention, the luminescence anisotropy changes in these embodiments as a function of the efficiency of the energy transfer or the lifetime of the excited states of the donor or acceptor, it being possible for both the luminescence anisotropy of the donor and that of the acceptor to change.

In some embodiments of the invention, regardless of the type of interaction of at least one luminescent dye with at least one cell structure, the condition of the cells is determined via the accessibility of the cell structure necessary for the interaction. In an advantageous embodiment of the invention, this can be used in particular to determine the integrity of cell membranes or cell walls and to determine the state of transport proteins, channels and endocytosis or exocytosis processes. Luminescent dyes according to the invention can be intrinsic molecules of the cells which are formed, consumed or excreted by them (for example NADH, NADPH, flavins, aromatic amino acids and their derivatives, porphyrins, pigments, fluorescent proteins, etc.). Luminescent dyes according to the invention can also be externally added molecules (for example neutral red, methylene blue, toluidine blue, DAPI, trypan blue, etc.). These can be part of the medium or added as required.

In an advantageous embodiment of the invention, the luminescence anisotropy of a luminescent dye is influenced by only one state of the cells, so that the state of the cells can be directly quantified via the quantification of the luminescence anisotropy.

In order to be able to detect significant differences in the luminescence anisotropy of an interacting and a non-interacting luminescent dye, depending on the resolution and sensitivity of the device according to the invention, the lifetime or time constant of the luminescence is shorter than the correlation time or correlation constant of the interacting luminescent dye in some embodiments of the invention and greater than the correlation time or correlation constant of the non-interacting luminescent dye. In other embodiments of the invention, for the same purpose, the correlation time or correlation constant of the interacting luminescent dye is up to 10 times, up to 100 times, up to 1000 times or more than 1000 times greater than the correlation time or correlation constant of the non-interacting luminescent dye.

In an advantageous embodiment of the invention, the luminescence anisotropy is determined as a ratiometric anisotropy value via the detection of the polarized emitted radiation for several, but at least two, different polarization angles. Advantageously, by using ratiometric anisotropy values, disadvantageous phenomena such as photobleaching, metabolism, new formation or decay of luminescent dyes can be avoided.

According to the invention, at least one anisotropy value is calculated from at least two luminescence values using suitable mathematical methods on at least one computer.

In some embodiments of the invention, to set at least two different polarization angles, the polarization of the exciting light is kept constant and the emitted light is polarized by at least one polarizer between the medium and at least one light sensor, the different polarization angles by the at least one polarizer or by several polarizers can be set in combination with one or more light sensors. In some other embodiments of the invention, to set at least two different polarization angles, the light is detected by at least one light sensor with constant polarization, while the polarization of the stimulating light is changed, for example by at least one variable polarizer in front of at least one light source or by several light sources with fixed ones integrated or external polarizers of different arrangements or light sources emitting polarized light with polarization-rotating optics (e.g. through retardation plates such as 1/2 plates).

In some embodiments of the invention, several, but at least two, luminescent dyes are used in order to be able to determine different states of cells simultaneously or sequentially (e.g. viability, metabolic activity, growth phase, contamination, etc.). According to the invention, the anisotropy values are then advantageously determined at different excitation or emission wavelengths.

In some embodiments of the invention, several, but at least two, luminescent dyes are used, which are used for the complementary determination of the same state (e.g. determination of the viability by determining the living cells with one and the dead cells with another luminescent dye). According to the invention, the anisotropy values are then advantageously determined at different excitation or emission wavelengths.

In an advantageous embodiment of the invention, at least one radiates during the detection of a luminescence value no light source light into the medium which has the same wavelength as the light emitted by at least one luminescent dye. In some embodiments of the invention, this is achieved by means of light sources with suitable wavelength characteristics (laser, LED). In other embodiments, this is achieved by combining at least one light source with at least one wavelength-selective optic, which advantageously only radiates light of the wavelength required for the excitation of the luminescent dye into the medium.

In an advantageous embodiment of the invention, there is at least one wavelength-selective optical system in the beam path between the medium and at least one light sensor, which ensures that the light sensor assigned to it only detects such light that has the correct wavelength. In an advantageous embodiment of the invention, light sensors in particular for detecting light emitted from luminescence processes are set up and provided with wavelength-selective optics in such a way that they exclusively or at least predominantly detect the emitted light and no other light, such as excitation light or ambient light. The same applies to sensors for detecting scattered light from stimulating and emitted light.

In some embodiments of the invention, a certain proportion of at least one luminescent dye is fixed by means of suitable methods in a defined state and thus with invariable luminescence anisotropy in order to act as a reference variable to which changes in the luminescence anisotropy can be related. In some embodiments of the invention, such references are permanently localized in patches within the reactor (e.g. by embedding in a gel or a plastic) and are evaluated via a separate reference channel consisting of a light source, polarizer and light sensor.

In some embodiments of the invention, the method according to the invention comprises the use of monochromators, filters, gratings or other wavelength-selective optics in order to separate the excitation light and the emission light for each luminescent dye. In an advantageous embodiment of the invention, the polarizers generate linearly polarized light.

In an advantageous embodiment of the invention, all optical components, as well as sensors, light sources and computers are located outside the reactor. In other embodiments, however, these can also be located inside the reactor, if appropriate with a suitable casing and optical windows, or they can be immersed in the medium as immersion probes.

In some embodiments of the invention, scattering of both the polarized exciting light and the emitted light can influence or falsify the determination of the anisotropy value. In order to counteract this and to correct scattered light artifacts by means of suitable mathematical methods, the method according to the invention includes in some embodiments the recording of scattered light values, in particular at the same polarization angles as when recording the luminescence values and in particular with the excitation and emission wavelengths used for the respective luminescent dye.

In some embodiments of the invention, at least one light source and at least one light sensor are arranged such that the volume containing cells in the common field of view of the at least one light sensor and the at least one light source is so small that the scattering of light within this field of view is very unlikely and thus the influence of light scattering on the determined anisotropy values is minimized or eliminated. According to the invention, this volume in the common field of view of at least one light sensor and at least one light source must be smaller with increasing cell density in order to efficiently prevent the scattering on the cells or cell structures. In some embodiments of the invention, the common field of view of at least one light sensor and at least one light source can therefore be variably adjusted by means of suitable optical or optomechanical devices. In some other embodiments of the invention, the common field of view of at least one light sensor and at least one light source is therefore designed so that up to a known maximum cell density in the medium no or only slight scattering effects which are acceptable for anisotropy detection occur. In some others Embodiments of the invention can prevent scattering effects as a function of the cell density by combining different light sources and light sensors to form at least one light source-light sensor pair. Different light sources and light sensors are arranged in such a way that a combination of at least one light source and at least one light sensor results in common fields of vision of different sizes, so that an optimum between minimum scattered light and maximum luminescence intensity can advantageously be achieved. In an advantageous embodiment of the invention, the cell density is also recorded in order to be able to assess the influence of scattering effects and to generate optimal light source-light sensor combinations as a function thereof. A wide variety of methods and devices are known to the person skilled in the art for determining cell density. In some embodiments of the invention, luminescence values of the same luminescent dye are recorded in parallel by several light source-light sensor pairs with different fields of view, in order to then use suitable mathematical methods to detect the influence of light scattering and to minimize or eliminate it in the calculation of the anisotropy value.

In some embodiments of the invention, the stimulating or emitted light is directed or otherwise influenced by fiber optic components, light guides or other optical elements such as lenses, diaphragms, slits, prisms or mirrors, in particular, but not exclusively, to optimal field of view geometries, field of view positions or field of view arrangements for light sensors or light sources to achieve.

In some embodiments of the invention, some or all of the components of the device according to the invention that lie in the beam path of the exciting or emitted light are remunerated or otherwise set up, manufactured or created in such a way that no or only one extremely low light scattering takes place in the range of the wavelengths used.

In some embodiments of the invention, the polarizers of the device according to the invention are in contact with the medium, so that apart from scattering effects within the medium and the cells, no further scattering effects occur Influence the detection of the luminescence values or the scattered light values. In some embodiments of the invention, the polarizers of the device according to the invention are integrated into the wall of the reactor for this purpose.

According to the invention, the emitted light can be detected at several, but at least two, different polarization angles, both in parallel and sequentially. In an advantageous embodiment of the invention, embodiments for the parallel detection of the emitted light at at least two different polarization angles include at least one polarizer with an associated light sensor for each polarization angle to be detected. Such methods can advantageously be implemented in devices according to the invention without the use of movable components, which is particularly desirable in harsh industrial, shaken or vibrating applications. Versions for sequential detection of the emitted light at at least two different polarization angles include at least one variable polarizer and at least one light sensor.

In some embodiments of the invention, the emitted light can be detected at several excitation and / or emission wavelengths. This can be done both in parallel and sequentially. In an advantageous embodiment of the invention, embodiments for the parallel detection of the emitted light at at least two different polarization angles include at least one polarizer with an associated light sensor for each polarization angle to be detected. Such methods can advantageously be implemented in devices according to the invention without the use of movable components, which is particularly desirable in harsh industrial, shaken or vibrating applications. Versions for sequential detection of the emitted light at at least two different polarization angles include at least one variable polarizer and at least one light sensor.

In some embodiments of the invention, several anisotropy values are recorded for a luminescent dye at different excitation and / or emission wavelengths. In particular, but not exclusively, this can be used to improve the resolution of cell states, to increase the robustness of the state determination and can be used to determine multiple states using the same luminescent dye.

In some embodiments of the invention, in particular in processes with continuous shaking operation, the luminescence values are advantageously recorded at a frequency that is greater than the shaking frequency in order to be able to compensate for the influence of different liquid distributions of the medium in the reactor. A wide variety of methods and devices are known to those skilled in the art for compensating and adapting optical measurements to dynamic fluid systems.

In an advantageous embodiment of the invention for dynamic fluid systems, in particular but not exclusively for continuously mixed reactors, all luminescence values or all luminescence values and scattered light values are recorded in parallel at the polarization angles provided according to the invention. This enables, in particular for the determination of ratiometric anisotropy values, the use of longer integration times, which also allow the detection of low-concentration luminescent dyes. If all luminescence measurements are carried out ratiometrically in parallel, the ratio of the individual luminescence values does not change, even if, for example, the absolute luminescence values change permanently due to periodic fluctuations in the liquid level during shaking operation.

In some embodiments of the invention, pulsed or otherwise modulated light sources are used for the purpose of ambient light compensation, so that the influence of ambient light on the determined anisotropy values can be minimized or eliminated by suitable signal processing of the luminescence and scattered light values.

In some embodiments of the invention, the temperature of the medium is recorded for each measurement in order to be able to correct influences of the temperature, in particular on the rate of rotation and diffusion of the luminescent dyes according to the invention, by means of suitable mathematical methods. According to the invention, individual anisotropy values are combined into time series that provide information about the condition or conditions to be determined over the entire course of a cultivation or other processing of cells and allow the user of the method according to the invention to draw conclusions about the biological events during the cultivation and subsequent process optimization .

The present invention is explained in more detail with reference to the figures and exemplary embodiments. Reference symbols in the figures which designate components of the invention which have already been used in the same figure or in another figure under the same circumstances or the same representation are partially omitted in order to maintain the clarity of the figures. Graphic elements without reference symbols are therefore to be interpreted taking into account the list of reference symbols, the other figures, the designated representations within the same figure, the patterning or structuring of already designated graphic elements and with reference to the entire description and the claims.

Embodiments and figures

Figure 1, a schematic representation of the method according to the invention.

FIG. 2, a schematic representation of the interaction of a luminescent dye according to the invention with a cell structure for determining the state of a cell.

FIG. 3, a schematic representation of the interaction of a luminescent dye according to the invention for determining the proportion of living cells.

FIG. 4, a schematic representation of the interaction of a luminescent dye according to the invention for determining the proportion of dead cells.

FIG. 5, a schematic representation of the interaction of a luminescent dye according to the invention for determining the proportion of infected cells. FIG. 6, a schematic representation of the interaction of a luminescent dye according to the invention for determining the proportion of infected and dead cells.

FIG. 7, a schematic representation of the method according to the invention with scattered light detection.

FIG. 8, a schematic representation of a device according to the invention with several light sources and light sensors.

FIG. 9, a schematic representation of a device according to the invention with several light sources and light sensors and with polarizers which are in contact with the medium.

FIG. 1 shows a schematic representation of the method according to the invention. In a reactor 3 filled with medium 2, cells 1 are cultivated, the condition of which is to be determined by means of the method according to the invention. This state determination takes place via the interaction of at least one luminescent dye 5 with a cell structure 1.1, this interaction leading to a change in the ambient conditions and thus to a change in the luminescence anisotropy of the luminescent dye 5. This is shown in Figure 1 as an interacting luminescent dye 5.1, which has a high luminescence anisotropy as a result of the interaction with the cell structure 1.1 (parallel filling), and as a non-interacting luminescent dye 5.2, which has a lower luminescence anisotropy due to the lack of interaction (corrugated Filling).

As shown in FIG. 1, the method according to the invention is characterized in that light 7 polarized by at least one light source 6 is radiated into the reactor 3 and the medium 2, where it excites molecules of the luminescent dye 5 to luminesce. The excited molecules of the luminescent dye 5 then emit light 8 which, depending on the proportions of the interacting luminescent dye 5.1 and the free luminescent dye 5.2, has a certain anisotropy with regard to the intensity distribution in the various planes of polarization. In an advantageous embodiment of the invention, the Wavelength of the polarized stimulating light 7 is smaller than that of the emitted light 8. According to the invention, at least part of the emitted light 8 leaves the medium 2 and, as shown in FIG. 1 as an advantageous embodiment of the invention, also the reactor 3 and is polarized by at least one polarizer 9 . The polarized emitted light 10 obtained in this way is detected as a luminescence value 12 by at least one light sensor 11. According to the invention, at least two luminescence values 12.1 and 12.2 are recorded, which differ with regard to the polarization angle of the polarized emitted light 10.1 and 10.2. For this purpose, the polarizer 9 according to the invention allows the polarization of light at at least two different polarization angles (shown as horizontal or vertical filling) and can in particular, but not exclusively, be designed both as a variable polarizer 9 or as a dedicated arrangement of differently oriented individual polarizers 9. According to the invention, the at least two luminescence values 12.1 and 12.2 recorded at different polarization angles are offset by means of suitable mathematical methods 13 to form at least one anisotropy value 14 which, as a result of the interaction-dependent luminescence anisotropy of the at least one luminescent dye 5, correlates with at least one state of the cells 1 and thus the determination of this State of cells 1 allowed.

In an advantageous embodiment of the invention, such ratios between the wavelengths l of the various light fractions as shown in FIG. 1 are used. Depending on the embodiment, these are separated from one another as far as necessary by suitable wavelength-selective optics 23, in particular but not exclusively by optical filters, monochromators, prisms, gratings or by complete or partial spectral scans (see also FIGS. 8 and 9).

FIG. 2 shows a schematic representation of the interaction of a luminescent dye 5 according to the invention with a cell structure 1.1 for determining the condition of cells 1. As an example, FIG. 2 shows a method for determining the proportion of living cells or viability. Cells 1 are cultivated in a reactor 3 filled with medium 2. In the living state, the cells have at least one cell structure 1.1 (in particular but not exclusively proteins, for example enzymes with NADH or NADPH as cofactor / substrate / product) with which at least one Luminescent dyes can interact (especially but not exclusively by binding). FIG. 2 shows an example of an intrinsic luminescent dye s (eg NADH, NADPH) which is formed inside living cells 1 (top left) and, due to its charge, cannot leave living cells 1 with an intact cell membrane. The intact cell membrane also represents a cell structure 1.3, which can be involved in the determination of the state of the cells 1 according to the invention because it defines and limits the localization of the luminescent dye 5. If the state of a cell 1 changes from alive to dead (bottom right), the cell membrane disintegrates (dashed border) and becomes a cell structure 1.2 permeable to the luminescent dye 5. Furthermore, in the embodiment of Figure 2 for dead cells 1 there is no longer any interaction between the luminescent dye 5 and the cell structure 1.1, in particular but not exclusively because the luminescent dye 5 dissociates from the cell structure 1.1 and diffuses through the disintegrated cell membrane 1.2 into the medium 2 or because the Cell structure 1.1 in dead cells 1 is no longer present or denatured. This makes it possible to determine the state of the cells 1 using the method according to the invention.

In FIG. 2, the luminescent dye 5.1 interacting with the cell structure 1.1 shows a high luminescence anisotropy, whereas the free luminescent dye 5.2 has a lower luminescence anisotropy. This is shown in FIG. 2, diagram A, as a luminescence value 12 as a function of the polarization angle. The interacting form of the luminescent dye 5.1 has high luminescence values 12 at low polarization angles and significantly lower luminescence values 12 at larger polarization angles. In contrast to this, the luminescence values 12 of the free luminescent dye 5.2 are distributed significantly more uniformly over the different polarization angles.

If, according to the example shown in FIG. 2, there is a mixture of living and dead cells 1 in the reactor 3, the interaction-dependent luminescence anisotropy of the luminescent dye 5, depending on the proportion of living cells 1, results in the mixed shown in FIG. 2, diagram B. Luminescence values 12 at the polarization angles shown. The detection according to the invention of at least two luminescence values 12.1 and 12.2 with different Polarization angles thus allow an assessment of the luminescence anisotropy. In an advantageous embodiment of the invention, the luminescence values 12.1 and 12.2 are preferably measured at polarization angles at which the difference in the luminescence anisotropy of the interacting form of the luminescent dye 5.1 and the free form of the luminescent dye 5.2 is particularly pronounced. Such a selection of the polarization angle is marked with arrows in FIG. 2, diagram B for the luminescence values 12.1 and 12.2. In particular, when referring to Figure 2, Diagram A, the difference in the luminescence anisotropies can be clearly seen, since at 0 ° polarization angle the luminescence value for the interacting luminescent dye 5.1 is significantly higher than that of the free luminescent dye 5.2. At a polarization angle of 40 °, these relationships are exactly the opposite.

According to the invention, at least one anisotropy value 14 is calculated from the at least two luminescence values 12.1 and 12.2 recorded at different polarization angles by means of suitable mathematical methods 13. This is shown by way of example in FIG. 2, diagram C for the luminescence values 12.1 and 12.2 shown in FIG. 2, diagram B. FIG. Of the many suitable mathematical methods 13, FIG. 2, diagram C, shows the subtraction of the luminescence value 12.2 from the luminescence value 12.1 and the division of the luminescence value 12.1 by the luminescence value 12.2. The subtraction thus gives a difference as anisotropy value 14 and the division gives a quotient as anisotropy value 14. These are plotted in FIG. 2, diagram C, against the proportion of the interacting luminescent dye 5.1. Since this proportion correlates with the state of the cells 1 as a result of the cell state-dependent interaction, it is clearly shown here that the anisotropy values 14 determined according to the invention can be used to determine the state of cells 1.

Figures 3 to 6 show schematic representations of the interaction of at least one luminescent dye 5 according to the invention for determining different states of cells 1. In a reactor 3, cells 1 are cultivated in the medium 2 contained therein, for each of which according to the invention at least one state via at least one anisotropy value 14 is to be determined, which via the interaction of at least one luminescent dye 5 with at least one cell structure 1.1 to 1.3 with the to determining state correlates. In the aforementioned figures, the interaction according to the invention of at least one luminescent dye 5 is shown schematically on the left, while the correlation between the state to be determined (on the X-axis) and the at least one anisotropy value 14 recorded according to the invention (on the Y-axis) is shown schematically on the right a luminescent dye 5 is shown as an example.

FIG. 3 shows a schematic representation of the interaction of a luminescent dye 5 according to the invention for determining the proportion of living cells 1. The luminescent dye 5 used here exhibits increased luminescence anisotropy when interacting with the cell structure 1.1. To determine the proportion of living cells 1, the luminescent dye s interacts with the cell structure 1.1, which is only present in living cells 1. In addition, the luminescent dye s accumulates in living cells 1, since these are surrounded by at least one intact cell membrane as cell structure 1.3. If the cells 1 die, the cell membrane becomes a permeable cell structure 1.2, so that the luminescent dye 5 diffuses out of dead cells 1 and is depleted there, and possibly and depending on the position of the interaction equilibrium, dissociates from the cell structure 1.1 that may still be present. This results in the correlation shown on the right between the proportion of living cells 1 and the anisotropy value 14. The more living cells 1 enriched with luminescent dye 5 and interacting with it via cell structure 1.1 compared to non-interacting dead cells 1, the higher the anisotropy value 14. In this respect, the anisotropy value 14 increases with the proportion of living cells 1 in the medium 2. In some embodiments of the invention, the anisotropy value 14 is converted into a percentage viability value. Examples of luminescent dyes that accumulate in living cells 1 are NADH / NADPH or neutral red, the former being formed by the living cell itself, whereas the latter diffuses from outside the cell uncharged across the cell membrane and then accumulates in acidic compartments as an "ion trap" in a charged state becomes. Exemplary cell structures 1.1 for interaction with NADH or NADPH are enzymes. Exemplary cell structures 1.1 for interaction with neutral red are lysosomes, endosomes and their membranes or membrane components. FIG. 4 shows a schematic representation of the interaction of a luminescent dye 5 according to the invention for determining the proportion of dead cells 1. The luminescent dye 5 used in this case shows increased luminescence anisotropy when interacting with the cell structure 1.1. In contrast to the embodiment shown in FIG. 3, the luminescent dye 5 is initially only present in the medium 2 and, in particular but not exclusively due to its charge, cannot reach living cells 1 via the cell membrane 1.2 in order to interact with the cell structure 1.1 there. However, since dead cells 1 have a holey membrane 1.2 that is permeable for the luminescent dye 5, it can get into the dead cells 1 and interact there with the cell structure 1.1. This results in the correlation shown on the right, the anisotropy value 14 increasing with an increasing proportion of dead cells. In some embodiments of the invention, the anisotropy value 14 is converted into a percentage viability value. Suitable luminescent dyes 5 for this embodiment are, for example, charged nucleic acid dyes such as propidium iodide with DNA or RNA as a cell structure 1.1 for interaction.

In some embodiments of the invention, the viability as the state of the cells 1 is determined by combining the determination of the proportion of living cells 1 (see FIG. 3) by means of a first luminescent dye 5 with the determination of the proportion of dead cells 1 (see FIG. 4) by means of a second Luminescent dye 5. In an advantageous embodiment, the two luminescent dyes differ in terms of their excitation or emission wavelengths. The viability is then determined using suitable mathematical methods 13 from the anisotropy values 14 recorded for each luminescent dye s used.

Figure 5 shows a schematic representation of the interaction of a luminescent dye 5 according to the invention for determining the proportion of infected cells 1. The luminescent dye 5 does not interact with a cell structure 1.1, but with a structure that is not actually part of the cell 1, in this case with a contamination 4 that is here in the cell 1 and has infected it, such as mycoplasma or viruses. The interaction of the luminescent dye 5 with at least one component of the contamination 4 increases its luminescence anisotropy, so that the luminescence value 14 detected according to the invention increases with the proportion of infected cells 1. Suitable luminescent dyes 5 can both be added externally, be located in the medium 2, or else be formed by the cells 1 themselves. In some embodiments of the invention, all cells 1 constitutively form an antibody fragment against a specific contamination (eg mycoplasma or virus). This antibody fragment is fused or conjugated with a luminescent dye 5 or a luminescent dye 5 binding structure, so that intracellular infections or contaminations 4 can be detected.

FIG. 6 shows a schematic representation of the interaction of several luminescent dyes 5A / 5B according to the invention for determining the proportion of infected and dead cells 1. In particular, the combination of different luminescent dyes for the simultaneous or parallelized determination of different states of cells 1 is shown combines an embodiment for determining the proportion of dead cells 1 from FIG. 4 via the luminescent dye 5B with an embodiment for determining the proportion of infected cells 1 from FIG. 5 via the luminescent dye 5A. According to the invention, several different states of cells 1 can thus be detected in parallel by combining suitable luminescent dyes 5. In an advantageous embodiment of the invention, the luminescent dyes 5 used differ with regard to their excitation wavelength or with regard to their emission wavelength or with regard to both of the aforementioned wavelengths.

FIG. 7 shows a schematic representation of the method according to the invention with scattered light detection. In a reactor 3 filled with medium 2, cells 1 are cultivated, the condition of which is to be determined by means of the method according to the invention. This state determination takes place via the interaction of at least one luminescent dye 5 with a cell structure 1.1, this interaction leading to a change in the ambient conditions and thus to a change in the luminescent anisotropy of the luminescent dye 5. This is shown in Figure 7 as an interacting luminescent dye 5.1, which has a high luminescence anisotropy due to the interaction with the cell structure 1.1 (parallel filling), and as a free luminescent dye 5.2 which has a lower luminescence anisotropy due to the lack of interaction (corrugated filling) . The one shown in FIG Execution of the method according to the invention extends the embodiment shown in FIG. 1 to include scattered light detection.

The method shown in FIG. 7 is characterized in that light 7 polarized by at least one light source 6.1 is radiated into the reactor 3 and the medium 2, where it excites molecules of the luminescent dye 5 to luminesce. The excited molecules of the luminescent dye 5 then emit light 8 which, depending on the proportions of the interacting luminescent dye 5.1 and the free luminescent dye 5.2, has a certain anisotropy with regard to the intensity distribution in the various planes of polarization. In an advantageous embodiment of the invention, the wavelength of the polarized exciting light 7 is smaller than that of the emitted light 8. According to the invention, at least part of the emitted light 8 leaves the medium 2 and, as shown in FIG. 7 as an advantageous embodiment of the invention, also the reactor 3 and is polarized by at least one polarizer 9. The polarized emitted light 10 obtained in this way is detected as a luminescence value 12 by at least one light sensor 11. According to the invention, at least two luminescence values 12.1 and 12.2 are recorded, which differ with regard to the polarization angle of the polarized emitted light 10.1 and 10.2. For this purpose, the polarizer 9 according to the invention allows the polarization of light at at least two different polarization angles (shown as horizontal or vertical filling) and can in particular, but not exclusively, be designed both as a variable polarizer 9 or as a dedicated arrangement of differently oriented individual polarizers 9.

The method shown in FIG. 7 is further characterized in that both the influence of the light scattering (e.g. on cells or other particles or interfaces) of the exciting light 7 and of the emitted light 8 is recorded and included in the processing to produce a scatter-corrected anisotropy value 22. For this purpose, in addition to the emitted light 8, the scattered light 16, which at least partially leaves the medium 2 or the reactor 3, is detected at the excitation wavelength, this being polarized by a polarizer 9 in the same at least two polarization angles of the polarized emitted light 10 and as polarized scattered light 18 (below at least two polarization angles as 18.1 / 18.2) with excitation wavelength through at least one Light sensor 11 is recorded as scattered light values 20 at the excitation wavelength (at at least two polarization angles as 20.1 / 20.2). Suitable wavelength-selective optics 23 can be used between medium 2 and light sensor 11 (e.g. grating in combination with a CCD line sensor) for the selective detection of the polarized scattered light 18 at the excitation wavelength without disturbing influences from ambient light or emitted light 8.

The method shown in FIG. 7 is further characterized in that the scattered light 17 which at least partially leaves the medium 2 or the reactor 3 is also detected at the emission wavelength. In order to quantify the pure scattering effect, when the light source 6.1 is switched off and the luminescent dye 5 is therefore not luminescent, light 15 polarized by at least one second light source 6.2 is radiated into the medium 2 or the reactor 3 to correct the scattering at the emission wavelength, where it is from cells or is scattered by other particles or interfaces and at least partially leaves the medium 2 or the reactor 3 again as scattered light at emission wavelength 17. The scattered light 17 at emission wavelength is polarized by at least one polarizer 9 at the same at least two polarization angles as the polarized emitted light 10 and recorded as polarized scattered light 19 (at at least two polarization angles as 19.1 / 19.2) at emission wavelength by at least one light sensor 11 as scattered light values 21 at emission wavelength (with at least two polarization angles as 21.1 / 21.2) For the selective detection of the polarized scattered light 19 at emission wavelength without disturbing influences of ambient light, suitable wavelength-selective optics 23 can be used between medium 2 and light sensor 11 (e.g. grating in combination with CCD line sensor) .

The method shown in FIG. 7 is further characterized in that from the at least two recorded luminescence values 12.1 / 12.2, the at least two recorded scattered light values at excitation wavelength 20.1 / 20.2 and the at least two recorded scattered light values at emission wavelength 21.1 / 21.2, all of which are at least equal to two polarization angles different from one another have been detected, at least one scatter-corrected anisotropy value 22 is calculated by means of suitable mathematical methods 13. In an advantageous embodiment of the invention, such ratios between the wavelengths l of the different light fractions as shown in FIG. 7 are used. Depending on the embodiment, these are separated from one another as far as necessary by suitable wavelength-selective optics 23, in particular but not exclusively by optical filters, monochromators, prisms, gratings or by complete or partial spectral scans (see also FIGS. 8 and 9).

FIG. 8 shows a schematic representation of a device according to the invention with a plurality of light sources 6 and light sensors 11 for carrying out the method according to the invention. The device comprises a reactor 3 in which cells 1 are cultivated in a medium 2. The device comprises two light sources 6, the wavelength ranges of the light source 6.1 and the light source 6.2 differing, so that either several luminescent dyes 5 can be evaluated in parallel (see also FIG. 6) or a scattered light correction can take place (see also FIG. 7).

The embodiment shown in FIG. 8 also includes four light sensors 11, each individual light sensor 11 being equipped with its own polarizer 9 and wavelength-selective optics 23 and being summarized as a detector set as A, B, C or D. They are similar the detector sets A / B or C / D, the selected wavelengths of the wavelength-selective optics 23, whereas the polarization angles of the polarizers 9 between the detector sets A / B and C / D are different. By using several light sensors 11 with associated wavelength-selective optics 23 and polarizer 9, the inventive detection of luminescence values 12 or scattered light values 20/21 and thus the determination of anisotropy values 14 can advantageously be parallelized.

The embodiment shown in FIG. 8 furthermore comprises a computer 24 which is connected to the light sensors 11 in order to control them and to receive data, in particular luminescence values 12 or scattered light values 20/21, from them. The computer 24 is also connected to the light sources 6 in order to control them or to receive data from them. The inventive determination of anisotropy values 14 from Luminescence values 12 or scattered light values 20/21 are carried out using suitable mathematical methods 13 on the computer 24.

In an advantageous embodiment of the invention, the optical components 9/23, light sources 6 and light sensors 11 of the embodiment shown in FIG. 8 are located outside the reactor 3, but in other embodiments they can also be located inside the reactor 3 or immersed in the medium 2 as immersion probes become.

FIG. 9 shows a schematic representation of a device according to the invention with a plurality of light sources 6 and light sensors 11 and with polarizers 9 which are in contact with the medium 2. The design is basically the same as the design shown in FIG. The only difference is the localization of the polarizers 9, which are in contact with the medium 2 in FIG. 9 in order to minimize or eliminate the scattering of light on optical elements, interfaces or other device components. In this embodiment of the invention, therefore, only scatter effects within the medium 2 influence the determination of anisotropy values 14.

A common polarizer 9 for the two light sources 6.1 / 6.2 is shown in FIG. 9, but in other embodiments this can also be part of the light sources 6 or be assigned to each individual light source 6 in some other way.

The contact of the polarizers 9 with the medium 2 shown in FIG. 9 can in particular, but not exclusively, be achieved by immersion probes and by integrating the polarizers 9 into the outer wall of the reactor 3, for example as a polarization filter film in disposable plastic reactors.

In summary, one of the objects of the present invention is to provide a method by means of which at least one state of cells in reactors can be determined without taking samples, without direct contact between the culture liquid and a sensor, with high parallelizability and miniaturization at the same time of the methods and devices to be used compared to the state of the art. According to the invention, the object is achieved, for example, by a method for determining the condition of cells in reactors, which uses the effect of luminescence anisotropy in order to be implemented as an optical method without direct contact with the culture liquid and with a high potential for minimization and parallelization. The method according to the invention is characterized in that polarized light is radiated into the medium from at least one light source and excites at least one luminescent dye to luminescence and that the light emitted by at least one excited luminescent dye at least partially leaves the medium and is polarized by at least one polarizer. It is also characteristic that the polarized emitted light obtained in this way is detected by at least one light sensor and that the polarized emitted light is detected at at least two different polarization angles as at least two luminescence values, from which at least one anisotropy value is determined by means of suitable mathematical processing, which as a result of the Environment dependency of the luminescent dye correlates with at least one state of the cells.

List of reference symbols

For the respective interpretation of the reference signs, the description and claims must be observed.

Claims

Expectations

1 . Method for determining the condition of cells 1, these being cultured in a medium 2 which is located in a reactor 3, with at least one luminescent dye 5 being located in reactor 3, the luminescence anisotropy of which is dependent on its ambient conditions, with at least one Ambient conditions of the luminescent dye 5 is influenced by at least one state of the cells 1, characterized in that light 7 polarized by at least one light source 6 is radiated into the medium 2 and stimulates the at least one luminescent dye 5 to luminescence and that that of at least one luminescent dye 5 emitted light 8 at least partially leaves the medium 2 and is polarized by at least one polarizer 9 and that the polarized emitted light 10 obtained in this way is detected by at least one light sensor 11 and that the polarized emitted light 10 under at least two different polarizations is detected as at least two luminescence values 12.1 and 12.2 and that at least one anisotropy value 14 is determined from the at least two luminescence values 12.1 and 12.2 using suitable mathematical methods 13, which correlates with at least one state of the cells.

2. The method according to the preceding claim, characterized in that the emitted polarized light 10 is separated from the exciting light 7 or ambient light by at least one wavelength-selective optics 23 and is thus preferably detected by at least one light sensor 11 for detecting at least one luminescence value 12.

3. The method according to the preceding claim, characterized in that several luminescent dyes 5 are used to determine several states.

4. The method according to any one of the preceding claims, characterized in that at least one used luminescent dye 5 is formed by the cells themselves.

5. The method according to any one of the preceding claims, characterized in that stray light values 20/21 are also recorded at the same polarization angles as the luminescence values 12 and are offset against the luminescence values 12 by means of suitable mathematical methods 13 to form at least one scatter-corrected anisotropy value 22.

6. The method according to any one of the preceding claims, characterized in that the temperature of the medium is also detected in order to be able to compensate temperature dependencies of the luminescence anisotropy of at least one luminescence dye 5 used.

7. Apparatus for performing the method according to any one of the preceding claims, comprising at least one reactor 3 which contains at least one medium 2 in which there are cells 1, wherein in the medium 2 or in the cells 1 at least one luminescent dye 5 is contained, its Luminescence anisotropy is to be determined, characterized in that the device comprises at least one light source 6 for irradiating polarized stimulating light 7 into the medium 2 and that the device comprises at least one light sensor 11 that detects polarized emitted light 10 and that the Device comprises at least one polarizer 9, which is designed so that the emitted light 8 can be polarized in at least two polarization directions, so that the at least one light sensor 11 can detect polarized emitted light 10.1 / 10.2 at at least two polarization angles.

8. Device according to the preceding claim, characterized in that at least one light source 6 or at least one light sensor 11 are each equipped with at least one wavelength-selective optics 23 so that at least one light sensor 11 cannot detect any light from at least one light source 6.

9. Device according to one of claims 7 and 8, characterized in that each light sensor 11 is equipped with its own polarizer 9 and wavelength-selective optics 23 as a detector set and that the device comprises at least one detector set for each luminescence value 12 and polarization angle to be detected.

10. Device according to one of claims 7 to 9, characterized in that at least one polarizer 9 is arranged in such a way that it is in contact with the medium 2.