Lymphoid cell line identification and the detection of cross contamination.

Four lymphoid cell lines, presumably recent derivatives from non-neoplastic human tonsils, were identified in actuality as established Burkitt lymphoma and lymphoblastoid cell lines (LCL) when tested by chromosome banding and typing for HLA antigens. Additionally, the morphology, growth characteristics, tumorigenicity, expression of Epstein-Barr virus antigens and surface membrane immunoglobulins (SmIg) of the four lymphoid cell lines confirmed the correct identifications. In determining the possibility of cross contamination, the most reliable criteria for the identification of lymphoid cell lines were found to be HLA antigenic profile, karyotype, cellular morphology, and growth characteristics.