Sandwich ELISA antibodies - (Sep/11/2006 )

Hi,

I have an polyclonal antibody specific for a protein (~20kDa). I want to quantify the protein in a sample using a sandwich ELISA. Can I use the same antibody for the capture part and then again for the detection part of the sandwich ELISA because it is polyclonal? or do I need to raise another antibody so that there are two separate antibodies for the antigen?

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Two different Abs certainly are better than one, and standard practice. Better still if one of them is a monoclonal. But you should get away with it as long as your Ab doesn't cross-react with anything to a significant level.

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You'll need to biotinylate the polyclonal in order to use the same ab for the detection step , otherwise you'll just detect the capture ab if you use an anti-species Ig HRP conjugate. (Alot of the R&D Systems kit use the same polyclonal, for capture without biotinylation and some biotinylated for the detection).

Ceri

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Thanks for the help. I kind of figured as much, however, I couldn't seem to find this information clearly stated.

All the best

Z

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