According to ICLAC (International Cell Line Authentication Committee) terms of reference, a cell line is considered to be misidentified if its DNA profile (genotype) is no longer consistent with the donor from whom it was first established. Such a cell line is described as a misidentified or false cell line .
To know if a cell line is authentic or misidentified, it is consequently important to look at its genotype and not its behavior (phenotype). Indeed, the cell line’s phenotype can vary with the passage number and/or the culture conditions. Misidentification can be due to several causes.
Whatever the problem, depending on the moment it occurs, a distinction is made between “false cell line” and “misidentified cell line”. If it happens early, during cell line establishment, no original material has been retained, and the cell line will be considered a false cell line. If it happens late, after the cell line has been established and distributed, the original material still exists. Only some stocks are therefore false and these will be defined as misidentified cells.