crp elisa - (Dec/22/2005 )

HI!
I have been trying to detect CRP production by hepatocytes using the culture media and ELISA kits with sensitivity of 1.9ng/ml. So far I have unable to do so. Can anyone help me with this????

Are you positive controls working?, If so your samples may not be concentrated enough, I've used cetrifuge concentrators made by millipore with success.

yes the ELISA is working as the positive control for the ELISA shows up but the experimental positive control does not show. The results are fine if you see them at the RNA level but I am having problems with detection of the same at the protein level.
Anyway thanks for your reply.