Conventional cytogenetics alone is not sufficient for identifying interspecies cell line contamination

Evidence from our laboratory suggests that conventional chromosome banding analysis alone is not sufficient for detecting interspecies contamination o f cell lines. To differentiate noncycling interphase cells of murine ol oth er species origin that may be contaminating a human cell line molecular cyt ogenetic techniques such as fluorescence in situ hybridization (FISH) with a total human DNA probe must be used.