HILIC or IEX better for protein digest?

[diablo]

Hi folks,

i'm trying to perform a high resolution peptide map of a protein digest (tryptic). I know RP seems to be the method of choice, but i wonder if i can get similar results with either HILIC or IEX ?

Which one is better ?

regards
diabloo

[Uwe Neue]

By virtue of the retention mechanism of RP, you will get better peak capacity from RP compared to IEX. With respect to HILIC, I have seen some very good resolution maps for very polar peptides that are barely retained in RP, but I do not recall having ever seen a complete digest with HILIC.

[Kostas Petritis]

I suggest that you have a look at the papers below (and selected references therein):

1)Hydrophilic interaction liquid chromatography (HILIC) in proteomics Anal Bioanal Chem (2008) 391:151–159

and

2) Mixed-mode hydrophilic interaction/cation-exchange chromatography (HILIC/CEX) of peptides and proteins J. Sep. Sci. 2008, 31, 2754 – 2773

[diablo]

ok, thx for your answers !