A comparison of immunohistochemistry and in situ hybridization for the detection of porcine circovirus type 2 in pigs.

The aim of this study was to develop and to optimize an immunohistochemistry (IHC) method for PCV2 identification and to compare it with an in situ hybridization (ISH) technique. The results demonstrated that both ISH and IHC successfully detected PCV2 viral antigens or nucleic acid in the examined tissues. Most of the slides identified previously in ISH as PCV2-positive were also positive in IHC. In the case of nearly half of the slides the results of IHC examination revealed an increase in the intensity of staining. IHC presented higher sensitivity and specificity than ISH. No negative impact of the time of paraffin block storage on ISH detection results was observed. In addition, IHC results were easier to interpret due to better image quality after staining. Overall results confirmed IHC was a reliable and useful technique for PMWS diagnosis.