a question about splitting MCF-7 cells - (Aug/18/2006 )

Hi,

I have a weird observation about my MCF7 cells. I splitted them on Wednesday and plated two 10-cm plate to carry, each having ~1 million cells. Today when I checked them under the microscrope, I found one plate is fine; in another plate, most of the cells were floating. Follows are how I splitted the cells on Wednesday: aspirated the old media, washed with 10-ml HBSS, added 1.1ml trypsin/EDTA to two plates of MCF-7 cells, after 10-min incubation added 8ml medium to each plate, pipette up and down several times, transferred all to a 50-ml tube, counting, mixed the desired amount with fresh medium to make 10-ml for each plate.

What might cause the floating of cells? I am wondering...

Thanks to anyone who can give me some clue!

Contamionations maybe? Did medium looked turbid? Colored yellow?

No. The medium looks normal. I guess I'll just toss away those cells. I still want to figure out why, so that the problem will not happen again.

may be faulty plate due to poor coating??

Remove trypsin after incubation, then pour the medium. When you count the sample with cells, put the rest of cells back in incubator. Oc it does not answer your question... Sorry. What I know is that these cells secrete some factors and need strong cell-cell contacts to grow well.

i had the same problem but with 293 A cells but i figured it happened to me when i left my cells for overgrowth over the weekend.