I am trying to do some home made ELISAs to look at antibody levels in serum. I am doing two ELISAs one looking at IgG1 antibodies the other for IgG2. I am running the two plates in parallel, everything is identical except for on one plate I put anti-IgG1 conjugate and the on the other plate anti-IgG2 conjugate. Each time I run the ELISA I see a high level of variation between duplicates on the IgG2 plate. Wheras the dupliates on IgG1 plate show low variation.
I just can't figure out why this is happening. Any advice?