Prevention of mycoplasma contamination in leukemia-lymphoma cell lines.

The contamination of cell lines with mycoplasmas is certainly one of the major problems occurring in cultured cells. Analyzing more than 460 human leukemia-lymphoma (LL) cell lines, we found that 28% of the cultures were mycoplasma-positive. Mycoplasmas can produce extensive changes, growth arrest and cell death in the infected cultures. While mycoplasma-infected cell lines can be truly cleansed from the contaminants, all the efforts would be in vain when the cells return to a mycoplasma-infested environment or are handled with unsuitable culture practices. Hence, the main focus of mycoplasma control should be on preventing cell culture contamination. Mycoplasmas can be introduced through several routes including culture reagents and laboratory personnel. Cross-contamination from infected cell cultures within one laboratory continues to be the major source for the spread of mycoplasma. Specific technical protocols and cell culturing guidelines may be followed in order to minimize the risk of mycoplasma contamination of cell lines. This "good culture practice" is of utmost importance as faulty cell culture techniques appear to be also the main reason for the high incidence of cross-contaminated LL cell lines which according to our experience using DNA fingerprinting of some 500 LL cell lines is about 15%.