Neuropeptide extraction from lysate for q-tof - (May/24/2006 )

Hi -I'm trying to extract neuropeptides from a whole organism lysate. Ive tried acidified acetone/methanol mixtures and TCA but with little success. Any ideas?

I read about pituary peptides extraction with mixture containing 1M HCl, 4% formic acid (v/v), 1% NaCl (w/v), 10% TFA (v/v). Extraction was followed by purification by SPE with use of C18 and ion exchange cartridges.

For peptides from dairy products we use methanol/chloroform followed by addition of water (if needed) to form methanol/water peptide-rich layer.