IgM for affinity chromatography

[NGUYENHD]

I have purified IgM antibody from my culture media by Sephacryl 300.  I have
also tried to couple this antibody to CNBr-activated Sepharose 4B.  Antibody
binds to the beads, but it loses its activiy and leaks with the eluting buffer
(0.1M Glycine, pH 2.5).  How do I get around these problems?

Thank you in advance.

Hung Nguyen
Biology Dept., Boston College
NGUYENHD at hermes.bc.edu