Misidentification and cross-contamination of mammalian cells applied in the field of biomedical research in cell STR identification has been a ubiquitous and outstanding problem.
According to statistics, about 20% of cell lines in foreign laboratories have been misidentified and cross-contaminated. NIH and ATCC have issued appeals for this in the past two years, requiring researchers to identify cells. In recent years, a large number of studies have shown that the STR genotyping method is one of the more effective and accurate methods for cell cross-contamination and character identification, and the application of STR genotyping in cell identification has been strongly recommended by ATCC and other institutions. The ATCC cell bank in the United States, the DSMZ cell bank in Germany, and the JCRB cell bank in Japan provided the data of each cell line for comparison of STR typing.
STR (Short Tandem Repeat, short tandem repeat sequence) gene locus is composed of short tandem repeat sequences with a length of 3-7 base pairs. These repeat sequences are widely present in the human genome and can be used as highly polymorphic markers. Known as the DNA fingerprint of the cell, it can be detected by PCR (polymerase chain reaction). Alleles at STR loci can be distinguished by differences in the copy number of repeat sequences within the amplified region, which can be identified by fluorescence detection after separation by capillary electrophoresis. Then, through a certain calculation method, the obtained STR typing results can be compared with the professional cell STR database to calculate the cell line to which the sample belongs or the name of the possible cross-contaminated cell line.