A new rapid immunohistochemical staining technique using the EnVision antibody complex

Rapid immunohistochemical investigation, in addition to staining with hemat oxylin and eosin, would be useful during intraoperative frozen section diag nosis in some cases. This study was undertaken to investigate whether the r ecently described EnVision system, a highly sensitive two-step immunohistoc hemical technique, could be modified for rapid immunostaining of frozen sec tions. Forty-five primary antibodies were tested on frozen sections from va rious different tissues. After fixation in acetone for 1 min and air-drying , the sections were incubated for 3 min each with the primary antibody, the EnVision complex (a large number of secondary antibodies and horseradish p eroxidase coupled to a dextran backbone), and the chromogen (3,3'diaminoben zidine or 3-amino-9-ethylcarbazole). Ail reactions were carried out at 37C. Specific staining was seen with 38 antibodies (including HMB-45 and antibo dies against keratin, vimentin, leukocyte common antigen, smooth muscle act in, synaptophysin, CD34, CD3, CD20, and prostate-specific antigen). A modif ication of the EnVision method allows the detection of a broad spectrum of antigens in frozen sections in less than 13 min. This method could be a use ful new tool in frozen section diagnosis and research.