BK polyomavirus (BKV), a DNA virus, is the second of two polyoma species. BKV infects a variety of urinary tract epithelia in immunocompromised patients and with increased frequency, patients with nephropathy and rejection renal transplant recipients. Use of the anti-SV40 monoclonal antibody, clone MRQ-4 will usually result in dense nuclear localization of the polyomavirus within renal tubules and urothelial cells. SV40 requires heat-induced epitope retrieval (HIER) pretreatment with citrate buffer (Ref4).
In the top image, SV40 antibody is reacting with BKV positive renal tubules from a renal transplant patient, utilizing DAB chromogen. In the lower image, SV40 antibody reacts with BKV positive renal tubules from a renal transplant patient, again using DAB chromogen.