Cell STR Authentication

Cell STR identification has long been a prominent issue in the field of biomedical research, especially concerning misidentification and cross-contamination of mammalian cells.

According to statistics, around 20% of cell lines in foreign laboratories are misidentified or contaminated. In the past two years, both NIH and ATCC have called on researchers to identify their cell lines accurately. In recent years, numerous studies have demonstrated that Short Tandem Repeat (STR) genotyping is one of the most effective and accurate methods for cell line authentication and cross-contamination detection. Organizations like ATCC strongly recommend the application of STR genotyping for cell identification. Cell line data from various institutions, such as the ATCC cell bank in the United States, DSMZ cell bank in Germany, and JCRB cell bank in Japan, are available for comparison purposes.

Short Tandem Repeat (STR) gene loci consist of short tandem repeat sequences of 3-7 base pairs. These repeat sequences are widely distributed in the human genome and serve as highly polymorphic markers, often referred to as DNA fingerprints of cells. The STR genotyping is performed using PCR (Polymerase Chain Reaction) to detect the repeat sequences. The different numbers of copies of the repeat sequences in the amplified region of the STR loci can distinguish alleles. After separation by capillary electrophoresis, the alleles are identified through fluorescence detection. Subsequently, by comparing the obtained STR genotyping results with professional cell STR databases using specific calculation methods, the cell line’s identity or potential cross-contamination can be inferred.