Inter- and intraspecies contamination of human breast tumor cell lines HBC and BrCa5 and other cell cultures.

It is shown that the two most recently reported cell lines derived from malignant human breast tissue, HBC and BrCa5 are, respectively, rat and HeLa cell contaminants. The incidence of inter- and intraspecies contamination among 279 cell cultures from 45 laboratories in an 18-month survey is also presented.