[IgG, modified with coproporphyrin I and the possibility of direct measurement of the antigen-antibody complex].

Modification of rabbit IgG by coproporphyrin I activated by Woodward's reagent K as well as antigen-binding and fluorescent properties of coproporphyrin-IgG have been studied. It was shown that coproporphyrin I modified IgG retains its capacity to bind the antigen. The formation of the immune antigen-antibody complex increases the intensity of coproporphyrin-IgG fluorescence.