Any experience with "Strep tag" fusion peptides & Strep-Tactin pur - (Jun/24/2008 )

I have been trying to purify a recombinant peptide coupled with a "Strep tag" at the C-terminal using Strep-Tactin columns (after ion-exchange chromatography) but it failed. I could detect around 90% of the peptide in flow through, a lot after washing the column & the remaining in elutes.

I appreciate it so much if any one shares his/her experience with me on this system.