Researchers working with immortalized cell lines would readily agree when I state that it is almost impossible to look at cells under the microscope and identify them by name. There are phenotypic traits, however they do change with change in media composition, passage number and in response to growth factors. I remember the pretty arborizations my neuroblastoma cell line SH-SY5Y exhibited in response to nerve growth factor treatment. Thus physical appearance is not a distinguishing feature. Currently, in many labs, researchers typically use more than one cell line, and more than likely, share the same lab space to passage cells and the same incubator to grow the cells. In such scenarios, it is not difficult to imagine that cell lines might get mislabeled or cross-contaminated. For example HeLa cells, one of the fastest growing cell lines have been shown to invade and overtake other cell lines.
Misidentification of cell lines has deep and severe implications. A review of cell lines used to study esophageal adenocarcinoma found that a large number of the cell lines were actually derived from lung or gastric cancers. Unfortunately, by the time this error was discovered, data from these cell line studies were already being used for clinical trials and other advanced studies and publications. Moreover, the cell lines were being to screen and design and test specific cancer drugs which ended up in flawed clinical trials. Continue reading ““Fingerprinting” Your Cell Lines”