In Vitro Testing

Microtest offers expert in vitro testing of biological samples for possible contamination by adventitious viruses — viruses not inherent to those samples. Our procedures are based on guidances from the U. S. Food and Drug Administration (FDA PTC 1993 and others) and the International Conference on Harmonisation (ICH Q5A). Customers may also request this testing be modified to accommodate certain other sample types, as desired.

Our in vitro testing has undergone validation per ICH guidelines. According to FDA and ICH guidances for viral safety, the testing requires that a sample of biological product is tested on a human and a primate cell line, as well as being tested on (at a minimum) a cell line of the species and tissue type that is used for production of the biological product.

In most cases, product samples are inoculated into each of the cell lines above, and the resulting inoculated cultures maintained for at least 14 days. The test is often extended to 28 days, especially in the case where the sample originates from a cell type that can support the replication of human cytomegalovirus. The cultures are observed regularly for the development of cytopathic effect (cpe) throughout the culture period.

At the end of the given period, Microtest virologists test the cultures for hemadsorption, or adherence of red blood cells to cell surfaces. The observation of cpe and/or hemadsorption indicates the presence of an adventitious agent. As a final result, we report whether adventitious viruses were detected in the sample. Reporting time for this in vitro testing is 5 weeks.

Our tests may be conducted in a variety of culture vessel sizes and with a variety of cell lines, as requested by the customer. Available cell lines include Vero, MRC-5, BHK-21, CHO-K1, NIH-3T3, SP2/0-Ag14, A9, A549, BT, GT, ST, MDBK, and more.

Call Microtest for information on standard protocols for test sample preparation, shipment, and packaging.