Differences in DNA fingerprints of continuous leukemia-lymphoma cell lines from different sources

The genetic stability of human cell lines in long-term culture has been tested by DNA fingerprinting a panel of 31 different continuous cell lines from patients with leukemias or lymphomas. Duplicates of the same cell line obtained from different sources, subclones of cell lines, and samples of cell lines at different passage levels were studied. In most cases the fingerprints of duplicates of the same cell line remained perfectly preserved even after long-time passaging. However, in five cases there were notable differences between individual fragments of corresponding fingerprints. We have found four cases of mislabeled and/or cross-contaminated cell lines so far. Taken together, our results indicate that DNA fingerprinting qualifies as a very reliable means of cell line identification which allows the detection of mislabelling or contamination and of genetic variation among subclones.