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Optimization, Design and Avoiding Pitfalls in Manual Multiplex Fluorescent Immunohistochemistry
Published on: July 26, 2019
Optimization of immunohistochemical methods using two different antigen retrieval methods on formalin-fixed
J A Ramos-Vara1, M E Beissenherz
1Veterinary Medical Diagnostic Laboratory, University of Missouri, Columbia 65211, USA.
Formalin fixation produces cross-links between the proteins and the fixative that alter the ability of some antibodies to recognize antigens. We used formalin-fixed, paraffin-embedded tissues to compare two different antigen retrieval methods for 63 antibodies used in the diagnosis of infectious and neoplastic diseases of animal species. Eighty-four percent of the antibodies needed some type of antigen retrieval for optimal results. Of those antibodies, 67.7% were monoclonal and 32.3% were polyclonal. Steam heat was the method of choice for 31 antibodies. Ten antibodies reacted only with steam heat, but 9 antibodies did not react when steam heat was used. Optimal results were obtained with enzyme digestion for 22 antibodies. Only 10 antibodies yielded optimal results without antigen retrieval; 64% of these antibodies were polyclonal. All antibodies against cytokeratins were optimally retrieved with proteinese K. Antigen retrieval appears to be necessary for the majority of antibodies when used with formalin-fixed, paraffin-embedded tissues.
Formalin fixation produces cross-links between the proteins and the fixative that alter the ability of some antibodies to recognize antigens. We used formalin-fixed, paraffin-embedded tissues to compare two different antigen retrieval methods for 63 antibodies used in the diagnosis of infectious and neoplastic diseases of animal species. Eighty-four percent of the antibodies needed some type of antigen retrieval for optimal results. Of those antibodies, 67.7% were monoclonal and 32.3% were polyclonal. Steam heat was the method of choice for 31 antibodies. Ten antibodies reacted only with steam heat, but 9 antibodies did not react when steam heat was used. Optimal results were obtained with enzyme digestion for 22 antibodies. Only 10 antibodies yielded optimal results without antigen retrieval; 64% of these antibodies were polyclonal. All antibodies against cytokeratins were optimally retrieved with proteinese K. Antigen retrieval appears to be necessary for the majority of antibodies when used with formalin-fixed, paraffin-embedded tissues.

