questions about mass spectrometry and cell culture - (Jul/19/2005 )

hi,

can i ask the following two questions:

1. if one liter of cell culture is grown to the later exponential phase and harvested, usually what is the wet weight of the cells? (just guess, can i get one gram of the wet weight of the cells from one liter culture?)
2. how much protein does it usually needed for mass spectrometry? in microgram, nanogram or picogram?

Thanks a lot!

I think it is more than nanogram level.
Several weeks ago I cut two protein bands from silver staining gel (silver quest kit). Both of those bands got low intensity on silver stained gel. However, the mass spectro could not identify them.

I think the protein amount was too little, although on the instruction page it is claimed that the sensitivity is comparable with mass spectro.

If you can observe the protein band on coomassie blue stained gel, I think the identification would have a much higher chance to succeed.

Good Luck!