Dear All I recently received a request for HMB45, MART-1, MiTF, S100 and Tyrosinase on sections of toe nail. Our laboratory will usually soften the toe nail in Potassium hydroxide (KOH) either before processing or sometimes after trimming the paraffin block and floating the block in a jar of KOH.
The pathologist was reasonably certain the nail contained melanoma yet the markers were all negative or at best, weakly postive. Thankfully there was a second specimen that, for whatever reason, had missed the KOH treatment. This stained with the markers as expected. Does anyone else use KOH for nail softening? Has anyone ever encountered a problem with KOH "knocking out" epitopes as described? Thanks Gary Gracie Senior Technical Officer IHC Laboratory Anatomical Pathology St Vincents Hospital Sydney, Australia ********************************************************************** This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify the system manager. This footnote also confirms that this email message has been virus scanned and although no viruses were detected by the system, St Vincents & Mater Health Sydney accepts no liability for any consequential damage resulting from email containing any computer viruses. ********************************************************************** _______________________________________________ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet