After cells are treated with TCA, how to resolve the protein in cell pellet? - (Jul/25/2006 )

I add 5%TCA to cell samples, then spin down and discard supernatant and keep pellet.
Now I want to test protein concentration. How to dissolve the pellet? I use cell lysis buffer, and it did not work well.

the important thing is to wash the acid before resuspending your proteins.
You can do that with ice cold acetone.
Then allow to air dry 30' at least and resuspend in cell lysis buffer.
That should do the job.

Thanks, Fred-33.
I washed pellet with acetone, and air dried it. But when added lysis buffer, the protein were still in pellet. How do you think? Do I need heat it?

resuspending proteins from acetone is in general also a tough procedure... and i do it by 37° on agitating thermoblock
So you have different possibilities.
1 : your cell buffer is sensitive to temp
2 : no sensivity.
In case 1, agitate at or in cold chamber
in case 2, agitate at 37° (25° if you suspect degradation may occur)

TCA precipitation is typically used to either concentrate protein samples, or remove low MW contaminants. What is the purpose of using TCA for your cells? can you do without it?