Contemination - (Feb/06/2007 )
We are grwong Hela cells in our lab but few days ago there appear small black spot along with the cells and within few days the cell loss their normal shape and shrink and died. we tried to fond the conteminatinon and check the culture for bacterial and fungal contemination, but there was not fungal or bacterial contemination. the black spot move randomly in media but very slowly and some part even do not move.
please guide me about the problem
1) bacteria (even though you say you checked): from the incubator, sloppy technique, contamination of reagents/materials.
Place a dish of media in the incubator, and leave it overnight or a day: if something grows in it then you will know that the contamination is from the media or the incubator. If it's the media, toss it. If it's the incubator, clean everything with 70% alcohol, even autoclave the shelves and sides if you can.
2) debris: maybe the cells are dying - have you changed anything in the media recipe?
3) contamination from the cell stock itself? Try another vial of cells.
4) precipitate from the media - try re-filtering the complete media through a 0.22mm filter.