Immunohistochemistry (IHC) plays a major role in the histopathological diagnosis of central nervoussystem (CNS) tumors. We developed a rapid immunohistochemistry (R-IHC) methodusing an alternating current electric field, which enables the completion of IHC in 20 min. Weperformed intraoperative R-IHC on 16 glioma patients (9 with grade I-III gliomas and 7 with glioblastomas)using the anti-mutant isocitrate dehydrogenase 1 (IDH1) monoclonal antibody (IDH1-R132H ; H09), and the results were validated on permanent formalin-fixed paraffin-embeddedsamples of the same patients by standard IHC. DNA sequencing of the IDH1 gene was also performedfor the 16 patients. Of 6 gliomas, 5 were shown to be positive by both R-IHC and standardIHC, and IDH1 mutation was confirmed by DNA sequencing. According to the results ofR-IHC compared with both standard IHC results and DNA sequencing, the sensitivity of IDH1R-IHC was 83% (5/6) ; specificity, 70% (7/10) ; positive predictive value, 63% (5/8) ; negativepredictive value, 88% (7/8) ; and accuracy, 75% (12/16). Thus, R-IHC using the anti-mutantIDH1 monoclonal antibody has potential applications in the intraoperative identification of IDH1mutations in gliomas
