Pesq. Vet. Bras. 28(12):627-632, dezembro 2008 RESUMO.-Para a padronização da técnica de imunohistoquímica para raiva foram utilizadas cinco amostras de SNC de bovinos infectados naturalmente com o vírus da raiva usando-se um anticorpo policlonal e dois monoclonais. Para a recuperação antigênica foram avaliados os seguintes reagentes: protease XIV, proteinase K e tampão citrato pH 6,0 mantido a 100°C por 15 minutos. A detecção de antígeno rábico nas amostras foi possível com os três anticorpos utilizados. O anticorpo policlonal foi superior aos anticorpos monoclonais, demonstrando bons resultados com os três protocolos de recuperação antigênica, obtendo uma maior intensidade de marcação quando utilizado o tampão citrato e calor. A técnica de imuno-histoquímica demonstrou a presença do antígeno viral no citoplasma de neurônios na forma de agregados de grânulos ou de forma redonda ou oval, mostrando cor- One polyclonal antibody and two monoclonal antibodies were used. The following reagents were evaluated for antigen retrieval: XIV protease, proteinase K and citrate buffer (pH 6.0) boiling at 100°C during 15 minutes in bain-marie. Detection of rabic antigen was possible with the three antibodies tested. The polyclonal antibody was superior to the monoclonal antibodies, demonstrating good results with the three antigen retrieval protocols. The highest intensity staining was obtained with the citrate buffer and heat. The immunohistochemistry technique demonstrated the presence of viral antigens in the cytoplasm of neurons, in form of aggregates or with round or oval shape. The antigens were found as single or multiples inclusion bodies in the neurons. Immunohistochemistry is a fast method that can be used in routine procedures in cases where rabies is suspected, especially when the brain is submitted to the laboratory as formalin-fixed fragments or when samples could not be immediately shipped. The technique is also useful for retrospective studies.INDEX TERMS: Diseases of cattle, infectious diseases, diseases of the central nervous system, rabies, immunohistochemistry standardization.
