Is TCA really specific in precipitating proteins from cell lysate? - (Jan/01/2008 )
I've seen that trichloroacetic acid (TCA) is a hot topic here. But still I'm confused over this "magic" chemical. I'm doing protein oxidatsion and lipid peroxidation work.
1. How specific is TCA in bring down proteins, not lipids and other things, from cell lysate?
2. Is it advantageous over other acids (phospheric acid, HNO3, H2SO4, HCl, phosphotungstic acid, etc) if protein denaturing is not a concern while protein oxidation is? I noticed that several of these acids are used in lipid peroxidation assay (TBARS assay) and what's more confusing, phosphotungstic acid is even used to bring down lipids from cell lysate!
I know little about chemistry and I have very limited experience only. So I hope many experts should be able to help me here. Thanks in advance! Happy new year to everybody!
In addition, it is said in a certain paper that if you put cell lysate into wells of some ELISA plates (not pre-coated with any antigen or antibody) and stay for a certain time for cellular components to adsorb, upon washing, proteins would still be adsorbed while non-protein constituents are easily washed away and so give minimal interference in protein oxidation assay.
1. Should I believe it?
2. IF this is true, what chemicals could make the ELISA plate so selective and by what mechanisms?
For those who are willing to have a look, I attached the paper. See the second sentence in "Principle" section). Thanks.