My cell culture has yeast contamination. I've tried nystatin at recommended concentration but just can't clean it up. Does anyone have an alternative to nystatin. Is it possible that the yeasts are resistant to nystatin (still there after 6 d of exposure to nystatin)?

debien:

Some resistance to nystatin in yeast has been reported by Patel, 1968 and Woods, 1971.

Here is a fairly comprehensive online guide to Understanding And Managing Cell Culture Contamination.

Here are some interesting articles about cell line contamination.




Rhitu Chatterjee
A Lonely Crusade
Science 16 February 2007:
Vol. 315. no. 5814, p. 930

"Walter Nelson-Rees drew hostility for exposing cell-line contamination, but his work is now being taken up by others.

n 1966, Stanley Gartler of the American Type Culture Collection found that 18 of the first 20 human cell lines established were chromosomally and biochemically identical to HeLa cells. All 18 lines were known to have come from Caucasian individuals. Yet Gartler found that each had a genetic variant of an enzyme found only in the small percentage of African-American population that Lacks had belonged to. Gartler published his findings in Nature in 1968, marking the first reported case of HeLa contamination. It was only the beginning.

A few years later, Walter Nelson-Rees began discovering contaminations in lines from laboratories across the world...."




Rhitu Chatterjee
When 60 Lines Don't Add Up
Science 16 February 2007:
Vol. 315. no. 5814, p. 929

"Even the bedrock of present-day cancer research, the NCI-60 panel--a group of 60 cancer cell lines maintained by the U.S. National Cancer Institute (NCI) and used widely for both basic research and drug discovery--has not escaped the scourge of cross contamination. In the late 1990s, Mordechai Liscovitch of the Weizmann Institute of Science in Rehovot, Israel, had obtained from the institute the breast cancer line MCF-7 and its drug-resistant daughter line, once known as MCF-7/AdrR (for Adriamycin resistance)--both part of the NCI-60 panel. A few years ago, a comparison of the lines in his lab revealed certain biochemical differences that illustrated how cancer cells become resistant to drugs. Three years of work with these lines had unfolded "a nice story," says Liscovitch...."




Rhitu Chatterjee
Cases of Mistaken Identity
Science 16 February 2007:
Vol. 315. no. 5814, pp. 928 - 931

"For decades, biologists working with contaminated or misidentified cell lines have wasted time and money and produced spurious results; journals and funding agencies say it's not their job to solve this problem..."

Point well taken. I'll ditch these cultures since I have back-up in cryostorage.