Potential of the in situ polymerase chain reaction in diagnostic cytology

Routine examination of cytologic material by light microscopy in our laboratory includes special stains and enzyme histochemistry, but molecular biology techniques are not generally employed. We examined the feasibility of utilizing the in situ polymerase chain reaction (PCR) for examination of archival cytologic specimens. Protocols were shortened in an effort to employ a technique that would be economical and have diagnostic relevance; a result would be obtained within two days of a request. Cases of transitional cell carcinoma were examined for the p53 tumor suppressor oncogene; preparation of direct incorporation PCR required eight hours of laboratory work, thermal cycling was performed overnight, and product visualization required three hours of laboratory work the following day. Amplification products were found in the cytoplasm and nuclear regions with an antidigoxigenin fluorescent and peroxidase probe. In situ PCR has enormous potential in the diagnostic cytology laboratory.