Research On Dynamic Cell Online Counting Method

Cancer is one of the leading causes of death in the world,and how to effectively cure cancer has always been a hot topic of concern.Immune cell therapy,as a new type of cancer treatment,has developed rapidly in recent years,showing a safe and effective potential for treatment.However,the preparation process of immune cell drugs is complex,and the high cost of treatment deters most patients,so immune cell therapy can not be popularized.How to transform the cellular drug preparation process into a large-scale automated production process is becoming more and more important.Only by reducing the production cost can more patients have access to this treatment method.Various sensors play a key role in the automated biological reaction process,and cell counting sensors are particularly important for cell therapy.Cell counting can not only be used to judge cell growth,but also an important parameter that needs to be mastered and controlled in all kinds of cell-related experimental research.Traditional cell counting methods can not meet the real-time on-line cell concentration detection and monitoring.Several on-line cell counting methods have been developed,among which the optical density method has the advantages of simplicity,rapidity and no labeling.As a simple and rapid indirect measurement method,optical density method can be used to estimate the biomass concentration in liquid cultures,and the wavelength and liquid medium have significant influence on the measurement effect of it.In this paper,the spectral scanning analysis of cancer cells of white blood cell lines and red blood cells was carried out,and the optimal wavelengths suitable for the measurement of leukocytes and erythrocytes were determined.First,different liquid media and leukocyte cancer cells were used for full-wavelength spectral analysis,and the corresponding robust wavelengths were found.According to the experimental results,it is suggested to measure the concentration of leukocytes and other suspended cells at near-infrared wavelengths(e.g.850 nm),so as to facilitate the subsequent unification of protocols applicable to different cell types and culture conditions.For erythrocytes,the wavelengths at which absorption peaks occur(540nm or580nm)have greater sensitivity and accuracy,and are more effective.Meanwhile,a portable dynamic cell counting sensor based on optical density was demonstrated.The sensor had good measurement stability for flowing cell suspensions to measure dynamic cell concentrations.Finally,the sensor was calibrated under different measurement conditions and different cell types,and the correlation between the output electrical signal of the instrument and the cell concentration was established.The sensor calibration curves under various experimental conditions all had high linearity,the regression coefficient R~2 was more than 0.99.Compared with the classic desktop spectrometer,the sensor occupies a small area and can be easily integrated into the automatic biological reaction system to realize on-line cell counting in the biological process.At the same time,it can significantly reduce the production cost,laying the foundation for large-scale application of biological manufacturing programs such as immune cell therapy.