In Vitro BrdUrd Labeling of Solid Tumors and Immunological Determination of Labeling Index

Abstract

The use of radioisotope-labeled DNA precursors like tritiated thymidine has made research into cell kinetics of human cancer difficult because of technical problems and the ethical problems involved in the use of human subjects. Once incorporated into the DNA of patients, these compounds remain there permanently. We have developed a simple and reliable combination of in vitro bromodeoxyuridine (BrdUrd) labeling and monoclonal immunocytochemical staining of biopsy and surgical specimens that provides an accurate estimate of DNA synthesizing cells within several hours after sampling. This method opens the way to realization of “dynamic” histopathology because neither radioisotopes nor time consuming autoradiography is required.