Background due to biotin label in ELISA - (Apr/04/2007 )

hi to all,
I have a problem...while performing ELISA...with biotinylated samples... in negative control also high background is comming. I am using high salt wash for one time (3 min) with PBST and PBS (3times for 3min each). Streptavidin HRP incubation for 45min. can any one help me to solve this problemm

what's your blocking buffer and incubation buffer?

[My blocking buffer is 0.5 % Gelatin in 50mM PBS and incubation buffer in 0.2% BSA in 50mM PBS. which has been standadized in the lab.....

has it been standardized for your application, with your samples and antibodies?