The necessity of identity assessment of animal intestinal cell lines: A case report

Eight intestinal cell lines, established from different animal species were submitted to DSMZ (German Collection of Microorganisms and Cell Cultures) in order to analyze their species of origin and their microbial contamination. Species identity was determined by PCR targeting mitochondrial genes and hence confirmed by sequencing the amplified PCR products. For three cell lines (CIEB, CLAB, PSI-1) we confirmed the species identity, whereas the species of origin of the three other cell lines (B6, B10XI and IPEC) was not the expected one: B6 and B10XI cells, which were supposed to be of chicken origin were identified as porcine cells. IPEC, allegedly a sub clone of the well-known porcine intestinal cell line IPEC-J2, was of bovine instead of porcine origin. However, two further IPEC-clones, namely IPEC-1 and IPEC-J2, provided by another source were shown to be derived from the correct species (i.e. pig). Furthermore, six out of these eight cell lines turned out to be highly contaminated with mycoplasma. Alerted by this high incidence of infected and false specified cell lines, we feel obliged to inform all those working with animal intestinal cell lines and we strongly recommend verifying the species identity before using them. Also, the presence of mycoplasma should be tested when taking the cells in culture for the first time, and this mycoplasma control should be repeated at regular time intervals (e.g. every 4 weeks).