Hi,

I have having an issue with the Fc blocking stages when carrying out flow cytometry on a murine macrophage cell line. I am using a rat anti-mouse antibody against the scavenger receptor MARCO. Unfortunately, I have been unable to find a conjugated version of this antibody and so I have a secondary goat anti-rat F(ab')2 to use with it. I have an Fc blocking solution, however this is also raised in rats and causes non-specific binding as the F(ab')2 fragment binds to this blocking solution as well as the primary antibody. I have been unable to find any Fc blocking solutions that are not raised in rat and I have tried various serums to try and block the Fc receptors instead, but have been unsuccessful (I have used a variety of mouse, goat, and FBS combinations).

I was wondering if anyone knows of any Fc blocks that are not raised in rat I could try, or whether there is any advice on how to get good blocking results using serum?

Thanks very much!