Methods for authenticating cell lines

Methods for authentication of cell lines include tests for microbial contamination, verification of the species of origin, documentation of particular characteristics or functions and the absolute identification of individual cell lines. Experience indicates that mycoplasma contamination is still a serious problem in the cell culture field, with estimates on frequencies of infection varying from 10% upwards. The utilization of pre-screened reagents and antibiotic-free cultivation, plus the application of improved procedures, such as fluorescent dyes and molecular probes for detection, provide effective means to avoid mycoplasma infection and facilitate control. Viral contamination is perhaps more problematic, especially where no overt cytopathic effect results. The potential exists for the introduction of viruses from the cell culture technician or reagents used. Representative problem viruses are listed with standard procedures for screening. Detailed studies on animal cell cross contaminations have been performed and published. The frequency of detection of problem culture varied from 17-36% in studies performed in the USA. Both interspecies and intraspecies contaminations have been involved. Awareness of the potential for this problem plus the application of several characterization procedures are key factors for control. For example, fluorescent antibody staining, iso-enzyme analysis, cytogenetic evaluation and DNA finger-printing using molecular probes are needed for quality assurance on seed stocks. The critical importance of generating well-characterized reference cell stocks for use over the years is emphasized.