Does anybody know secondary antibody conjugated to non-fluorescent color ? - (Mar/05/2014 )
I can check the color by light microscope without fluorescent light source.
You can get ones with reactive moieties which generate colour when incubated with a substrate such as DAB. There are quite a few others too.
Thank you for your input! I want to use this with other fluorophores. I am not quite sure whether enzymatic reaction interferes with others. So I'd love to find one with direct observation.
You can get gold particle labeled ones, but they usually need to be visualized using specialist techniques such as EM or certain types of light microscopy. The problem with using direct visualization is the size - molecules are typically very very small and given that an antibody will bind 1:1 with its target, you won't be able to see the interaction directly. Hence the use of flurophores and reactions, which create visible spots by spreading out the signal.