Expression of Ki-67 in paraffin embedded biological tissues (breast cancer specimens)
33 breast cancer specimens were examined for possibilities of antigen activity reduction of biological tissue fixed in formalin and paraffin embedded. Parallel sections were used, immunohistochemistry was performed with Ki-67 as a proliferation marker. It is statistically and reliably established that antigen activity in a paraffin-embedded section reduces better in a pressure cooker than in a water bath. Incorrect performing immunohistochemistry results in erroneous interpretation.