Mycoplasma, the smallest and self-replicating prokaryotes, are common contaminants of primary cells and cell lines. Mycoplasma contamination can affect cell growth, morphology and metabolism. Mycoplasma are able to pass through 0.2 µm filters due to their small size. Furthermore, unlike bacteria and fungi, mycoplasma contamination is resistant to commonly used antibiotics, and can not be identified visually. Due to the difficulties in detecting mycoplasma, cells should be regularly screened to control mycoplasma contamination. Conventional screening methods include microbiological culture, fluorescent DNA staining, and biochemical detection methods, and are typically time consuming and lack sensitivity. As a result, polymerase chain reaction (PCR) based methods have been developed as a quick and convenient detection of low level mycoplasma infection, while providing high sensitivity and specificity. Alignment studies of mycoplasma 16S rRNA sequences revealed the existence of highly conserved sequences. Primers targeting these sequences allow for the specific amplification of the mycoplasma DNA fragment. ScienCell™ Mycoplasma PCR Detection Kit is a 16S rRNA-based PCR assay consisting of 2×PCR master mix (which includes PCR buffer, DNA polymerase and dNTPs), mycoplasma primer set, and a positive control, which is noninfectious genomic DNA (gDNA) of M. fermentans. The genus-specific primer set recognizes the five typical contaminating mycoplasma species (i.e., M. hyorhinis, M. arginini, M. orale, M. fermentans, and A. laidlawi), which account for 98% of contamination, as well as members of the genera Ureaplasma, Spiroplasma, and Acholeplasma, which account for the remaining 2% of contamination. Eukaryotic and bacterial DNA is not amplified by this kit. The size of the expected band is 280 bp.