© DR. MICHAEL GABRIDGE/VISUALS UNLIMITED/CORBISMycoplasma are everywhere. Members of this genus of bacteria are the smallest free-living organisms able to self-replicate. In the 1950s, when mycoplasma were first isolated from cell cultures, contamination was found in 57–92 percent of lab-grown cells. Because the organisms lack a cell wall, they are resistant to common antibiotics, such as streptomycin and penicillin, and they easily slip through filters.
Even though scientists are now more aware of mycoplasma as possible contaminants, it is estimated that as much as 35 percent of the cell cultures currently used in research may be infected. It remains a common problem—especially in university labs, where trainees come and go, and cell lines freely change hands—partly because the bacteria are impossible to see using conventional microscopy. They also produce indirect, subtle effects on eukaryotic cells.
Bakhos Tannous, an associate professor of neurology at Harvard Medical School, says he “learned the hard way” about mycoplasma contamination in his cell-culture rooms years ago. Now the group tests routinely, so they were surprised when recent results came back positive. This time, however, the degradation of a bioluminescence reporter Tannous’s group was using in ...
