Just revived a sw480 cells from a 2019 batch.
Was normal on the first 2 days. After 5 day, the culture media became cloudy, and lot of suspicious white dots.
Is this yeast contamination, as I have never encountered this before.
Hello Jung Yin Fong
Yes, it is yeast contamination. At 100x magnification you will find yeast cells as separate round or ovoid particles or in chains of two to four or more particles and can sometimes be multi-branched. The appearance of chains is due to the most common form of replication called budding. You will find that yeast cells are larger than bacterial cells but smaller than the mammalian cells.
In early stages of contamination, you will not observe any change in growth media. But as the infection increases, the culture media will turn cloudy.
For more information on yeast contamination you may want to refer to the link below.
https://unclineberger.org/tissueculture/contaminant/yeastcontam/#:~:text=Typical%20routes%20of%20infection%20in,surfaces%20during%20cell%20culture%20manipulation.
Best.