Back to In Vitro Testing

The 1993 'Points to Consider in the Characterization of Cell Lines Used to Produce Biologicals' (FDA/CBER 1993) guideline notes that human epithelial cell lines and all cells used for live virus vaccine production should be tested for tumorigenicity. Moreover, some special cases that involve somatic cell or gene therapy products could also require tumorigenicity testing. In contrast, rodent cells need not be tested for tumorigenicity because virtually all continuous cell lines of rodent origin have been shown to be tumorigenic. Typically, testing is performed on cells at the limit of in vitro cell age. Using the in vitro model, soft agarose, can assess tumorigenic potential of a cell line. Many transformed cells, including continuous cell lines, differ from their untransformed diploid counterparts in their capacity to remain viable and replicate when suspended in soft agarose due to a decreased requirement for cell-to-cell and cell-substrate adhesion for proliferation. Clonogenicity in soft agarose is a useful in vitro technique for assessing the neoplastic potential of transformed cells.