any way to inactivate trypsin without using FBS? - (and still let cells survive ^__^) (Dec/16/2008 )

Dear all,

I need to do some exps that require me to first trypsinize the cells, then allow them to grow in 2 different conditions: 1) normal (with FBS), and 2) without FBS (in medium containing B27)

The problem is, after trypsinizing the cells, in case number 2, how do I make sure to get rid of the trypsin? In exp 2, I don't want the cells to get into contact with any serum after trypsinization. Do I just simply spin cells down, take off the medium, and wash a few times? How many times will be sufficient? Or is there any other ways? If anyone can help out a bit, please?

Thank you very much in advance.

I would go with the washing of cells with its own medium. It all depends on what is the density of your cells. If you have more than 10'6 you can wash at least twice. If it is less than that; only once. In every wash you loose about from 3,000 to 5,000 cells depending on your tube.

Soy bean trypsin inhibitor is the way to go.

Thank you for your quick responses. Yes, I did think about trypsin inhibitor. After that you have to wash again, right? Actually, this is the question I ask for my labmate's exp. She got 66 soft agar exps to do, and to wash 66 tubes, well... Not to mention if she duplicate, or tryplicate... But I suppose no choice, huh.

Thanks again. You guys are the best,