The successful propagation of any cell line requires adherence to established protocols. Preparation of frozen cell stocks and the successful recovery and expansion of the cells for virus isolation are critical techniques to acquire. Training for laboratories in the GMRLN is available and all laboratories should have SOPs in place for all steps in cell culture propagation and processing for virus isolation. Annex 5.1 includes protocols and guidelines that can be used to develop the laboratory SOPs for propagation, maintenance and preparation of frozen cell stocks of Vero/hSLAM cell culture.
Network laboratories should only accept Vero/hSLAM cells from a WHO-approved source (RRL or GSL). These RRL or GSL laboratories follow the protocols for the propagation of the Vero/hSLAM cell culture that maintains and verifies the expression of SLAM. In addition, the laboratories that provide the cell line will ensure that the cell lines are susceptible to infection with wild-type measles viruses and are free of mycoplasma contamination. Upon receipt, the cells should be passaged in cell culture medium containing 400 µg/ml Geneticin®. The cells are passaged forward (usually 2 times), increasing the number of flasks to provide a sufficient quantity of cells to prepare 20-50 vials of cell stock for liquid nitrogen storage (refer to annex 5.1).