Abstract for Lonza Biologics Poster:

The productivity of a cell line selected for the manufacture of a biopharmaceutical has a major influence on the economics of the production of that molecule. Expression systems, including those based on the glutamine synthetase system, can yield highly productive stable cell lines. It is nevertheless important when developing such cell lines to monitor cell line stability. Cell encapsulation technology, such as that offered by the One Cell Gel Microdrop system, can be used to rapidly monitor changes within a cell population by flow cytometry.

The cell encapsulation technology was first developed using relatively low producing hybridoma cell lines. When this system was first tested with a highly productive recombinant GS-NSO cell line, leakage of excess product out of the microdrop masked the presence of non-producing sub-populations. Following optimisation, the technique could quantify the presence of non-producing cells when they were present at 5% or greater of the population. The limit of detection for the presence of non-producing cells within a population was approximately 0.1%. This methodology has been developed to complement more traditional techniques for examining cell line stability. A study determining its value in cell line development programmes will be presented.