help: Drosophila cell culture - (Dec/27/2005 )

Hi, everyone
I'm fairly new to the Drosophila cell culture. Some days ago, I thawed the S2 cells. After the overnight incubation, I found some dark dots in the medium. And the blank medium (Schneider's medium) incubated overnight also have some dark dots, but the medium didn't become cloudy. After 5 days, the blank medium still clear but have some dark dots. On the other hand, I incubated the medium with 10% FBS and FBS alone. The medium with FBS bcame cloudy after overnight incubation, some dark dots can be found, while FBS clear and also had some dark dots. After 5 days, the number of dots didn't increase. I want to know what the dots are and whether the cells are contaminated by bacteria. Did the similar thing happen to you? Can you tell me the details about your Drosophila cell culture? I appreciate any information that can give help to solve this problem. Thank you very much.
Happy New Year to all!

I started S2 cells culture only recently. For my case, I did see dark elongated cells which stick to the bottom, I think they are dead Drosophila cells. I am not sure what kinda dark spots u have noticed. Another I would like to ask, I purchased my Schneider's Drosophila Medium from Gibco, and usually they come without L-glutamine added, I am not sure how much L-glutamine I should add, but according to the manual I found online, they said 1800mg/L. How much l-glutamine did you add to your medium? Whether or not your cells tend to stick to the bottom of the flask? (does it mean they are dead?) If they tend to clump together when there are too many cells in a flask?


Best wishes,
Will