It is essential that cells in culture and in cryopreservation are free of microbial contamination. In order to corroborate this, cells need to be periodically tested for bacterial and fungal contamination. Mycoplasma is a large group of tiny bacteria, about 0.3-0.8 um in diameter, all lacking a rigid cell wall belonging to the Mollicultes class of bacteria. Unlike other bacterial contaminates, the media will not change turbidity from a mycoplasma infection and therefore it will go undetected unless the culture is tested for mycoplasma. Due to the lack of a rigid cell wall and their small size, they are very difficult to eliminate once they contaminate a culture. Since mycoplasma have no rigid cell wall, it is difficult to be killed by antibiotics that can only mask the infection. These organisms can pass through the 0.22 micrometer filters commonly used for the sterile filtration of media and reagents. There are many methods available to detect mycoplasma contamination. ISENET detect mycoplasma contamination in cell lines by using PCR based method that is characterized by a higher sensitivity and precision compared to the detection by luminescence-linked enzymology, fluorescent staining methods or culture, in addition to the fact that samples do not need to be vital. The method allows the detection of M.orale, M. hyorhinis, M. arginini, M. fermentans, M. salivarium, M. hominis, usually encountered as contaminants in cell cultures, but also M. pneumonie, Acholeplasma laidlawi, M. synoviae and Ureaplasma species.