Molecular detection of cell line cross-contaminations using amplified fragment length polymorphism DNA fingerprinting technology

Transformation and Tumorigenicity Testing of Simian Cell Lines and Evaluation of Poliovirus Replication

The key role of cell cultures in different scientific fields is worldwide recognized, both as in vitro research models alternative to laboratory animals and substrates for biological production. However, many safety concerns rise from the use of animal/human cell lines that may be tumorigenic, leading to potential adverse contaminations in cell-derived biologicals. In order to evaluate the suitability of 13 different cell lines for Poliovirus vaccine production, safety and quality, in vitro/in vivo tumorigenicity and Poliovirus propagation properties were evaluated. Our results revealed that non-human primate cell lines CYNOM-K1, FRhK-4, 4MBr-5 and 4647 are free of tumorigenic features and represent highly susceptible substrates for attenuated Sabin Poliovirus strains. In particular, FRhK-4 and 4647 cell lines are characterized by a higher in vitro replication, resulting indicated for the use in large-scale production field.

DNA profiling and characterization of animal cell lines

The history of the culture of animal cell lines is littered with published and much unpublished experience with cell lines that have become switched, mislabelled, or cross-contaminated during laboratory handling. To deliver valid and good quality research and to avoid waste of time and resources on such rogue lines, it is vital to perform some kind of qualification for the provenance of cell lines used in research and particularly in the development of biomedical products. DNA profiling provides a valuable tool to compare different sources of the same cells and, where original material or tissue is available, to confirm the correct identity of a cell line. This chapter provides a review of some of the most useful techniques to test the identity of cells in the cell culture laboratory and gives methods which have been used in the authentication of cell lines.

An alternative method to isoenzyme profile for cell line identification and interspecies cross-contaminations: cytochrome b PCR-RLFP analysis

One of the major risks in cell culture laboratories is the misidentification and cross-contamination of cell lines. Several methods have been used to authenticate cell lines, including isoenzyme profiling, the test suggested by European Farmacopeia, which is performed at the Tissue Culture Centre in Brescia. However, this method displays several disadvantages, such as high variability and low reproducibility, and it is time consuming and requires high cell concentrations to be performed. Therefore, an alternative method has been developed to confirm the specie of origin of 27 different animal cell cultures. A polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) assay was optimized, based on the use of a pair of primers that anneal to a portion of the cytochrome b gene in all the species. The amplification product was digested with a panel of six restriction enzymes, and the pattern derived was resolved on 3% high-resolution agarose gel. For 23 species, this protocol produced a unique restriction pattern, and the origin of these animal cells resulted to be confirmed by this analysis. Furthermore, results indicate that cytochrome b PCR-RFLP was able to amplify target sequences using very low amounts of deoxyribonucleic acid (DNA). Its sensitivity in detecting interspecies, cross-contamination was comparable to that of isoenzyme analysis (contaminating DNA should represent at least 10% of the total DNA). For 4 of the 27 species (sheep, dog, Guinea pig, and Rhesus monkey) the observed pattern, even if highly reproducible, showed additional bands; for these species, specific PCR was also performed.

Identification and verification of rodent cell lines by polymerase chain reaction

Cell lines represent valuable tools for basic research and diagnostic applications as well as for the production of biological products such as antibodies or vaccines. For all cell culturists, a well-identified origin of their cell lines as well as the periodic re-examination of their identity should be a basic requirement. We established a simple polymerase chain reaction (PCR) to verify or identify rodent and human cell lines. Since mouse-, rat-, Chinese hamster- and Syrian hamster-derived cell lines represent the most frequently used rodent cell lines, our investigations were focused on these species. Our assay used oligonucleotide primers annealing to sequences within the beta-actin and the beta-globin gene and to repetitive DNA. Primers were designed mostly from intron sequences of the genes aiming to amplify only one specific DNA segment and thus enabling to exclude easily false DNA. More than 130 cells lines originating from the five species were analyzed in that study. Our PCR revealed specific profiles for all species investigated. No further methods like DNA sequencing or fragment length polymorphism analysis were needed to differentiate these species. The results introduce our PCR-assay as a rapid, specific and routinely feasible tool in order to identify or distinguish rodent cell lines from each other and from human cell lines.

Eradication of cross-contaminated cell lines: A call for action

This "white paper" was prepared and widely disseminated in an attempt to sound an alarm about the long-term existence of a grave, unresolved and growing problem that affects a significant portion of biomedical research, namely, the use of misidentified and cross-contaminated cell cultures. The "white paper" shows how bold action could bring about a profession-wide change in practice that would prevent further erosion. Misidentification and inter- and intra-specific cross-contamination of mammalian cell cultures used in research continues as a widespread problem despite an awareness that dates back more than 45 years. Awareness of the problem has led to a good understanding of the causes of cross-contamination and appropriate preventive measures. It has also led to the application of robust methods for the authentication of cell lines. Yet the problem continues unabated. Estimates of the incidence of research papers flawed by the use of misidentified and cross-contaminated cell cultures approximate 15-20%. The gravity of the situation calls for a strategy that would deliver a remedial message of authentication to virtually all cell culture researchers and also ensure compliance with the message. At the core of the strategy proposed herein is having cell line authentication as a condition for the award of research grants and for the publication of research findings.