Cell culture monitoring method
Technical Field
The invention relates to the field of life science research, in particular to a cell culture monitoring method capable of continuously and quantitatively monitoring a cell culture state.
Background
In cell culture and regenerative medicine research, continuous monitoring of cell culture is very important, and conditions of the culture medium such as temperature, humidity, pH value and the like are usually required to be adjusted, so that monitoring of the culture medium is critical to cell culture, and the state of the culture medium in a cell culture chamber is usually controlled by exchanging with fresh culture medium or monitoring pH value, but these methods depend on the experience and ability of laboratory personnel, so that it is very important to develop a device for continuous monitoring and quantitative estimation of the culture medium and the cell state. The prior art methods for evaluating the state of cell culture by using devices include the yield estimation of products such as proteins and amino acids and the recovery of the culture medium, and the corresponding state is usually determined by measuring the light absorption of each species in the culture medium, but because the light detection efficiency in the detection experiment is low, the cell culture chamber needs to be taken out of the incubator, and the cover of the cell culture dish needs to be opened, so that the pollution is easily introduced and the experimental steps are complicated, and the cell culture monitoring method can solve the problems.
Disclosure of Invention
In order to solve the above problems, the method of the present invention uses a special optical waveguide to guide light passing through the culture medium to a photodetector, and can monitor the state of cell culture continuously and quantitatively without changing the culture environment.
The technical scheme adopted by the invention is as follows:
the cell culture monitoring device comprises a light source base, nine light-emitting diodes, a pore plate, nine sample chambers, a detector base, nine optical waveguides, nine optical detectors, a cable and a computer, wherein xy z is a three-dimensional space coordinate system, the light-emitting diodes emit white light, a cell culture sample is arranged in each sample chamber, the light source base is positioned at a position 12 mm above the pore plate, the pore plate is provided with nine sample chambers arranged in a 3 x 3 matrix form, the nine light-emitting diodes are arranged on the lower surface of the light source base in a 3 x 3 matrix form, the nine light-emitting diodes are respectively and correspondingly positioned right above the nine sample chambers, the nine sample chambers are all cylindrical pits with upward openings, the detector base is connected below the pore plate, the detector base is provided with nine optical waveguides arranged in a 3 x 3 matrix form, the nine optical waveguides are respectively and correspondingly positioned right below the nine sample chambers, the side surfaces of the optical waveguides are provided with light absorption coatings I with the thickness of 200 micrometers, each light absorption coating I is composed of a mixture of carbon black particles and a polysiloxane compound, the outer sides of the light absorption coatings I are covered with light absorption coatings II with the thickness of 500 micrometers, each light absorption coating II is composed of a mixture of a multi-walled carbon nanotube and polydimethylsiloxane, the lower surfaces of the nine optical waveguides are correspondingly provided with optical detectors, each optical detector is provided with a color sensor, the optical detectors are sensitive to light with the wavelengths of 620 nanometers, 530 nanometers, 460 nanometers and 860 nanometers, the nine optical detectors are all connected with a computer through cables, and the optical detectors can output detection results to the computer through 16-digit digital signals; the light source base is a square plastic sheet with the thickness of 2 mm and the side length of 30 mm, the light emitting diode is a cylinder with the height of 6 mm and the diameter of the bottom surface of 2 mm, the pore plate is a square glass sheet with the thickness of 5 mm and the side length of 30 mm, the diameter of the bottom surface of the sample chamber is 5 mm and the depth of 4 mm, the detector base is a square glass sheet with the thickness of 12 mm and the side length of 30 mm, the light guide is a cylinder with the height of 7 mm and the diameter of the bottom surface of 1 mm, the light guide is made of a transparent polysiloxane compound, the diameter of carbon black particles is 200 nm, the mass ratio of the carbon black particles of the light absorption coating I to the polysiloxane compound is 9: 1, and the mass ratio of the multi-walled carbon nano tube of the light absorption coating II to the polydimethylsiloxane is 5.
The cell culture monitoring method comprises the following steps:
step one, calibrating the relation between the solution concentration in the sample chamber and the light absorption measured by the light detector by adopting a methylene blue solution:
respectively placing the aqueous solutions of methylene blue with the concentrations of 2 micromolar, 4 micromolar, 8 micromolar, 15 micromolar, 20 micromolar, 25 micromolar, 30 micromolar, 50 micromolar and 70 micromolar in each sample chamber, starting the light-emitting diode, recording the light intensity and wavelength information of the solutions passing through each sample chamber by using a light detector, and calculating to obtain the absorption log (I) of the solutions with the concentrations to light0/It) In which I0Is the initial light intensity of light with the wavelength of 620 nanometers in white light emitted by the light emitting diode, ItThe light intensity of light which is measured by the light detector and is 620 nanometers, penetrates through the cell culture sample and enters the light detector;
step two, calibrating the relationship between the pH value in the sample chamber and the light absorption measured by the light detector by using a culture medium to be measured:
the known pH values of 7.0, 7.2, 7.4, 7.8, 8.0, 8.4, 8.8, 9.0 and 9.4 to be measuredThe culture medium is placed in each sample chamber, the light emitting diode is started, the light detector is adopted to record the light intensity and wavelength information of the culture medium passing through each sample chamber, and the absorption value log (I) of the culture medium with different pH values to light is calculated0/It) In which I0Is the initial light intensity, I, of light with the wavelength of 530 nanometers in white light emitted by a light emitting diodetThe light intensity of light transmitted through the cell culture sample and entering the light detector at 530 nm as measured by the light detector;
mixing nine identical cell culture samples to be detected with a fresh culture medium, placing the mixture into nine sample chambers, starting the light-emitting diodes, recording the light intensity and wavelength information of the culture medium passing through each sample chamber by using the light detectors, and measuring the value log (I log) of the absorption of light of 620 nanometers by using the nine light detectors0/It) Averaging to obtain the absorption of the cell culture sample to be detected to the light of 620 nanometers, and comparing with the relation between the solution concentration in the sample chamber obtained in the step one and the light absorption measured by the optical detector to finally obtain the concentration of the cell culture sample to be detected and the concentration of the culture medium;
step four, the step four and the step three are carried out simultaneously, and the value log (I) of the absorption of the light with the wavelength of 530 nanometers measured by nine photodetectors0/It) And averaging to obtain the absorption of the cell culture sample to be detected to 530 nm of light, and comparing with the relationship between the pH value in the sample chamber obtained in the step two and the light absorption measured by the light detector to finally obtain the pH value of the cell culture sample to be detected and the pH value of the culture medium.
The invention has the beneficial effects that:
the method of the invention adopts the optical waveguide made of special materials, has high light detection sensitivity, and can continuously and quantitatively monitor the state of cell culture without changing the cell culture environment.
Drawings
The following is further illustrated in connection with the figures of the present invention:
FIG. 1 is a schematic of the present invention;
FIG. 2 is a perspective view of a light source base, aperture plate, and detector base.
In the figure, 1, a light source base, 2, a light emitting diode, 3, a pore plate, 4, a sample chamber, 5, a detector base, 6, an optical waveguide and 7, a light detector are arranged.
Detailed Description
FIG. 1 is a schematic view of the present invention, FIG. 2 is a schematic perspective view of a light source base, a pore plate and a detector base, which includes a light source base (1), nine light emitting diodes (2), a pore plate (3), nine sample chambers (4), a detector base (5), nine optical waveguides (6), nine photodetectors (7), a cable and a computer, xy z is a three-dimensional space coordinate system, the light emitting diodes (2) emit white light, a cell culture sample is disposed in the sample chambers (4), the light source base (1) is a square plastic sheet with a thickness of 2 mm and a side length of 30 mm, the light source base (1) is disposed at 12 mm above the pore plate (3), the pore plate (3) is a square glass sheet with a thickness of 5 mm and a side length of 30 mm, the pore plate (3) has nine sample chambers (4) arranged in a matrix of 3 × 3, the nine light emitting diodes (2) are mounted on the lower surface of the light source base (1) in a matrix of 3 × 3, nine light-emitting diodes (2) are respectively and correspondingly positioned right above nine sample chambers (4), the light-emitting diodes (2) are cylinders with the height of 6 mm and the diameter of the bottom surface of 2 mm, the nine sample chambers (4) are all cylindrical pits with upward openings, the diameter of the bottom surface of each sample chamber (4) is 5 mm and the depth of 4 mm, a detector base (5) is a square glass sheet with the thickness of 12 mm and the side length of 30 mm, the detector base (5) is connected below a pore plate (3), nine optical waveguides (6) arranged in a 3 x 3 matrix form are arranged on the detector base (5), the optical waveguides (6) are cylinders with the height of 7 mm and the diameter of the bottom surface of 1 mm, the optical waveguides (6) are made of a transparent polysiloxane compound, the nine optical waveguides (6) are respectively and correspondingly positioned right below the nine sample chambers (4), the side surfaces of the optical waveguides (6) are respectively provided with a light absorption coating I with the thickness of 200 microns, the light absorption coating I is composed of a mixture of carbon black particles and polysiloxane compounds, the diameter of the carbon black particles is 200 nanometers, and the mass ratio of the carbon black particles to the polysiloxane compounds of the light absorption coating I is 9: 1; the outer side of the light absorption coating I is covered with a light absorption coating II with the thickness of 500 micrometers, the light absorption coating II is composed of a mixture of multi-walled carbon nanotubes and polydimethylsiloxane, the mass ratio of the multi-walled carbon nanotubes to the polydimethylsiloxane of the light absorption coating II is 5: 1, a light detector (7) is correspondingly installed below nine optical waveguides (6), the light detector (7) is provided with a color sensor, so that the light detector (7) is sensitive to light with the wavelengths of 620 nanometers, 530 nanometers, 460 nanometers and 860 nanometers, all the nine light detectors (7) are connected with a computer through cables, and the light detector (7) can output detection results to the computer through 16-bit digital signals.
The principle of the invention with higher light detection sensitivity is as follows: the white light emitted by the light emitting diode (2) irradiates on the cell culture sample in the sample chamber (4) and is absorbed in different degrees at certain wavelengths, a part of light which is not absorbed by the cell culture sample passes through the bottom surface of the pore plate (3) and is transmitted into the optical waveguide (6), the light is reflected and scattered at the interface between the cell culture sample and the bottom surface of the sample chamber (4) and the interface between the bottom surface of the pore plate (3) and the optical waveguide (6) to generate stray light, so that the signal-to-noise ratio of the optical detector (7) is influenced, because the light absorbing coating I and the light absorbing coating II on the side surface of the optical waveguide (6) have strong light absorption, therefore, most of the stray light can be coated by the light absorption layer, and only the light which propagates along the negative y direction can enter the light detector (7) through the optical waveguide (6), so that the light detection sensitivity is improved.
The cell culture monitoring device comprises a light source base (1), nine light emitting diodes (2), a pore plate (3), nine sample chambers (4), a detector base (5), nine optical waveguides (6), nine optical detectors (7), a cable and a computer, wherein xyz is a three-dimensional space coordinate system, the light emitting diodes (2) emit white light, cell culture samples are arranged in the sample chambers (4), the light source base (1) is positioned at 12 mm above the pore plate (3), the pore plate (3) is provided with nine sample chambers (4) arranged in a 3 x 3 matrix form, the nine light emitting diodes (2) are arranged on the lower surface of the light source base (1) in a 3 x 3 matrix form, the nine light emitting diodes (2) are respectively and correspondingly positioned right above the nine sample chambers (4), the nine sample chambers (4) are cylindrical pits with upward openings, the detector base (5) is connected below the pore plate (3), nine optical waveguides (6) arranged in a 3 x 3 matrix form are arranged on the detector base (5), the nine optical waveguides (6) are respectively and correspondingly positioned right below the nine sample chambers (4), the side surfaces of the optical waveguides (6) are respectively provided with a light absorption coating I with the thickness of 200 micrometers, the light absorption coating I is composed of a mixture of carbon black particles and polysiloxane compounds, the outer side of the light absorption coating I is covered with a light absorption coating II with the thickness of 500 micrometers, the light absorption coating II is composed of a mixture of multi-walled carbon nanotubes and polydimethylsiloxane, a light detector (7) is correspondingly arranged below the nine optical waveguides (6), and the light detector (7) is provided with a color sensor, the light detectors (7) are sensitive to light with wavelengths of 620 nm, 530 nm, 460 nm and 860 nm, nine light detectors (7) are all connected with a computer through cables, and the light detectors (7) can output detection results of 16-bit digital signals to the computer; the light source base (1) is a square plastic sheet with the thickness of 2 mm and the side length of 30 mm, the light emitting diode (2) is a cylinder with the height of 6 mm and the diameter of the bottom surface of 2 mm, the pore plate (3) is a square glass sheet with the thickness of 5 mm and the side length of 30 mm, the diameter of the bottom surface of the sample chamber (4) is 5 mm, the depth is 4 mm, the detector base (5) is a square glass sheet with the thickness of 12 mm and the side length of 30 mm, the optical waveguide (6) is a cylinder with the height of 7 mm and the diameter of the bottom surface of 1 mm, the optical waveguide (6) is made of a transparent polysiloxane compound, the diameter of carbon black particles is 200 nm, the mass ratio of the carbon black particles to the polysiloxane compound of the light absorption coating I is 9: 1, and the mass ratio of multi-wall carbon nano tubes to polydimethylsiloxane of the light absorption coating II is 5: 1.
The cell culture monitoring method comprises the following steps:
step one, calibrating the relation between the concentration of the solution in the sample chamber (4) and the light absorption measured by the light detector (7) by adopting a methylene blue solution:
respectively adopting 2 micromolar, 4 micromolar, 8 micromolar, 15 micromolar, 20 micromolar, 25 micromolar, 30 micromolar, 50 micromolar and 70 micromolar aqueous solutions to be placed in each sample chamber (4), starting the light-emitting diode (2), recording the light intensity and wavelength information of the solution passing through each sample chamber (4) by using a light detector (7), and calculating to obtain the value log (I) of the absorption of the solution with each concentration to light0/It) In which I0To emit lightInitial intensity, I, of light with a wavelength of 620 nm in the white light emitted by the diode (2)tThe light intensity of the light of 620 nm measured by the light detector (7) which penetrates through the cell culture sample and enters the light detector (7);
step two, calibrating the relationship between the pH value in the sample chamber (4) and the light absorption measured by the light detector (7) by using a culture medium to be measured:
placing culture media to be detected with known pH values of 7.0, 7.2, 7.4, 7.8, 8.0, 8.4, 8.8, 9.0 and 9.4 into each sample chamber (4), starting the light emitting diode (2), recording the light intensity and wavelength information of the culture media passing through each sample chamber (4) by using the light detector (7), and calculating to obtain the absorption log (I) of the culture media with different pH values to light0/It) In which I0Is the initial light intensity, I, of light with the wavelength of 530 nanometers in the white light emitted by the light emitting diode (2)tThe light intensity of light measured by the light detector (7) at 530 nm transmitted through the cell culture sample and entered the light detector (7);
mixing nine same cell culture samples to be detected with a fresh culture medium, placing the mixture into nine sample chambers (4), starting the light-emitting diodes (2), recording the light intensity and wavelength information of the culture medium in each sample chamber (4) by using the light detectors (7), and measuring the absorption value log (I) of light with 620 nanometers by using the nine light detectors (7)0/It) Averaging to obtain the absorption of the cell culture sample to be detected to the light of 620 nanometers, and comparing with the relation between the solution concentration in the sample chamber (4) obtained in the step one and the light absorption measured by the light detector (7), so as to finally obtain the concentrations of the cell culture sample to be detected and the culture medium;
step four, the step four and the step three are carried out simultaneously, and the value log (I) of the absorption of the light with the wavelength of 530 nanometers measured by the nine photodetectors (7) is measured0/It) And averaging to obtain the absorption of the cell culture sample to be detected to the light of 530 nanometers, and comparing the absorption with the relation between the pH value in the sample room (4) obtained in the step two and the light absorption measured by the light detector (7) to finally obtain the pH value of the cell culture sample to be detected and the pH value of the culture medium.
The method can measure the pH value change of the culture medium in real time under the condition of not changing the culture environment, and can detect the concentration change of the culture medium with high precision.