• human retina;
  • carbonic anhydrase;
  • isoenzyme C;
  • immunohis-tochemistry

The occurrence of carbonic anhydrase isoenzymes C and B in the retina of the human eye was examined with specific antisera against these enzymes. Immunological analyses were carried out by the double diffusion method of Ouchterlony, and the localization of the enzymes was studied by an application of immunoperoxidase (PAP) technique. A large amount of isoenzyme C was detected in tissue sections from the human retina, whereas the isoenzyme B was totally absent. Isoenzyme C was considered to be located primarily in the glial elements of the retina, correlating with the earlier findings obtained by traditional metal salt methods.