This question is part of the following Ask The Expert session:
A) Companies looking to implement a cell line authentication program need to decide if they wish to perform the testing internally or reference the samples to a laboratory specializing in cell line authentication. To test internally, the technology currently recommended by ANSI-ATCC standards is STR DNA analysis. This would require purchasing a genetic analyzer, thermal cyclers, and other supporting equipment. The laboratory would also need fragment analysis software and training to interpret the STR profiles and mixtures, as well as, training on identifying and troubleshooting anomalies. The commercial kits available for STR profiling should be validated at a minimum for reproducibility and sensitivity. Choice of kit would also be a consideration. Mixtures, which are common in cell line authentication testing, should also be validated as part of the setup. Some guidance on running and interpreting STR profiles can be found at ATCC SDO, Authentication of Human Cell Lines: Standardization of STR Profiling ATCC SDO document ASN-0002. Manassas, VA: ATCC Standards Development Organization, 2011.
Outsourcing the samples has the advantage of no capital expenses, no validation studies or training needed, and the reference laboratory should be able to generate appropriate reports. The company seeking a provider can find a number of qualified laboratories on the internet. Accreditation by an organization with standards for STR DNA profiling methods may also be desirable. Examples of accreditation agencies would be AABB, the College of American Pathologists (CAP), ISO (usually ISO 17025 or 15189) and various forensic organizations.
B) You should consider performing cell line authentication when a cell line is acquired, before starting a new series of experiments, when results using the same cell line are inconsistent or unexpected, to establish a STR DNA profile for a new established cell line, prior to freezing cell stocks for future use and every 2-3 passages during active growth. Ideally, for new “in-house” developed cell lines you would compare a low passage number of the established cell line to the original patient from which the cell line was derived (blood or solid tumor sample); this sets the “reference” profile for all future authentication testing with that cell line. If you plan to publish, checking with the journal you would like to publish in for their requirements, if any, may be prudent.
C) Failure to test your cell lines for authenticity could lead to compromised data – it is estimated that up to 40% of all published peer reviewed papers are affected by cell line misidentification and/or cross-contamination (Chatterjee, Science, 2007). There have been retractions of journal articles due to this problem – one example is the 2005 discovery that stem cells could seed cancer (Garcia-Castro, J. et al, Can Res, 2005). In 2010 this article was retracted because the authors were unable to reproduce some of the reported spontaneous transformation events; a contamination with the human cancer cell line HT-1080 was identified as the source of the problem (Garcia, S. et al, Exp Cell Res, 2010).