(516a) Use Of Focussed Beam Reflectance Measurement (Fbrm) For Monitoring Changes In Cell Populations In Hybridoma Cultures

Mammalian cell culture technology underpins the success of the rapidly growing biopharmaceutical industry. It is essential to maintain high cell numbers and viability to maximise the productivity of a culture. Focussed beam reflectance measurement (FBRM) offers the potential for in situ monitoring of cell density and viability which would be extremely useful for the development and optimisation of such cultures. FBRM is an optical monitoring technique which is used where analysis of particle size and shape is important. FBRM utilises laser light backscatter technology to supply a chord length distribution (CLD) in real time. Typically, thousands of particles are measured during one measurement duration. The purpose of this research was to investigate the potential of using FBRM as a process monitoring technique in mammalian cell cultures. The relationship between the total number of particles counted by the probe and the cell concentration was found to be highly linear within the range of 5.5 x 10⁵ to 1.2 x 10⁷ cells/ml. The response to apoptosis in cell suspensions was also investigated. It was observed that the total number of particles counted increased with decreasing viability and there was a downward trend in the median, mean and mean square-weighted of the CLDs which reflects the decrease in cell size with the onset of apoptosis. The work to date has demonstrated the potential of FBRM as an optimisation tool within mammalian cell culture.