We present a panoptic survey of cell line cross-contamination (CLCC) among original stocks of human cell lines, investigated using molecular genetic methods. The survey comprised 252 consecutive human cell lines, almost exclusively tumor-derived, submitted by their originators to the DSMZ and 5 additional cell repositories (CRs), using a combination of DNA profiling (4-locus minisatellite and multilocus microsatellite probes) and molecular cytogenetics, exploiting an interactive database (http://www.dsmz.de/). Widespread high levels of cross-contaminants (CCs) were uncovered, affecting 45 cell lines (18%) supplied by 27 of 93 originators (29%). Unlike previous reports, most CCs (42/45) occurred intraspecies, a discrepancy attributable to improved detection of the more insidious intraspecies CCs afforded by molecular methods. The most prolific CCs were classic tumor cell lines, the numbers of CCs they caused being as follows: HeLa (n ‫؍‬ 11), T-24 (n ‫؍‬ 4), SK-HEP-1 (n ‫؍‬ 4), U-937 (n ‫؍‬ 4) and HT-29 (n ‫؍‬ 3). All 5 supposed instances of spontaneous immortalization of normal cells were spurious, due to CLCC, including ECV304, the most cited human endothelial cell line. Although high, our figure for CCs at the source sets a lower limit only as (i) many older tumor cell lines were unavailable for comparison and (ii) circulating cell lines are often obtained indirectly, rather than via originators or CRs. The misidentified cell lines reported here have already been unwittingly used in several hundreds of potentially misleading reports, including use as inappropriate tumor models and subclones masquerading as independent replicates. We believe these findings indicate a grave and chronic problem demanding radical measures, to include extra controls over cell line authentication, provenance and availability. Int.

Inter- and intraspecies cross-contaminations (CCs) of human and animal cells represent a chronic problem in cell cultures leading to false data. Microsatellite loci in the human genome harboring short tandem repeat (STR) DNA markers allow individualization of cell lines at the DNA level. Thus, fluorescence polymerase chain reaction amplification of STR loci D5S818, D13S317, D7S820, D16S539, vWA, TH01, TPOX, CSF1PO, and Amelogenin for gender determination is the gold standard for authentication of human cell lines and represents an international reference technique. The major cell banks of the USA, Germany, and Japan (ATCC, DSMZ, JCRB, and RIKEN, respectively) have built compatible STR databases to ensure the availability of STR reference profiles. Upon determination of an STR profile of a human cell line, the suspected identity can be proven by online verification of customer-made STR data sets on the homepage of the DSMZ institute. Furthermore, an additional tetraplex PCR has been established to detect mitochondrial DNA sequences of rodent cells within a human cell culture population. Since authentic cell lines are the main prerequisite for rational research and biotechnology, the next sections describe a rapid and reliable method available to students, technicians, and scientists for certifying identity and purity of human cell lines of interest.

The main prerequisition for any research, development, or production programs involving cell lines is whether a cell line is authentic or not. Microsatellites in the human genome harboring short tandem repeat (STR) DNA markers allow the identification of individual cell lines at the DNA level. Polymerase chain reaction (PCR) amplification of eight highly polymorphic microsatellite STR loci and gender determination have been proven to be the best tools for screening the uniqueness of DNA profiles in an STR database. The main Biological Resource Centers (BRCs), ATCC, DSMZ, JCRB, and RIKEN, have generated large databases of STR cell line profiles for identity control. In cooperation with the Japanese BRCs, DSMZ has piloted the generation of the most comprehensive international reference database, which is linked to a simple search engine for interrogating STR cell line profiles. The tool of online -verification of cell line identities is available on the respective homepages of JCRB and DSMZ ( http://cellbank.nibio.go.jp/cellbank_e.html , http://www.dsmz.de/STRanalysis ). The following sections describe a rapid, practical, inexpensive, and reliable method available to students, technicians, and scientists.

No abstract

No abstract