MMP 9 isolation using sepharose beads - tagging gelatin to sepharose beads (May/25/2009 )

hello every one,

i need to purify MMP9 from conditioned media so i need gelatin tagged to sepharose beads. So any one have protocol how gelatin is tagged to sepharose beads.

thanks in advance,
alie.

Wouldn't it be better to immunoprecipitate with an antibody and protein A or G sepharose beads?