I'm culturing cells in 6-well plates to expose them to a drug for 24h.
They are grown in media with antibiotics and serum.
After they're reached around 80-90% confluency, I swap the media with serum-free media containing my drug solution.
However, after 24h all the wells are cloudy.
Since this is the second time this has happened, I was extra careful during the second run - consistently spraying the hood and even wiping the closed plate edges with ethanol. I changed pipette tips frequently. I follow strict aseptic technique, that also includes aliquotting of media, not moving arms above plates etc.
Under the microscope it looks like a layer of small dots.
What could this be?
I'm at a loss.
It cannot be the media or cells since they grow fine in 96-well plates and work well doing the exposures.
Could it be from touching the inside edge of a well when slowly adding the new media?
Edited by mia123, 08 May 2018 - 08:03 AM.