In my suggestions, I assume you have a bioassay or immunoassay for
the peptide.
Two quick thoughts:
1.) Pellet proteins, etc with 50% aq. ethanol, rotovap the spnt to remove
the ethanol and purify by IEX (if possible) or SEC, followed by RP-HPLC.
or
2.) Pellet proteins, etc with appropriate NH4SO4 concentration to leave
peptide in solution. Run peptide fraction through HIC, followed by
RP-HPLC
good luck,
Hank Wolfe
Nycomed Amersham
Philadelphia, Pa.