There are three main diagnostic techniques used for the diagnosis of the reactivation of polyomavirus in polyomavirus nephropathy (PVN): urine cytology, quantification of the viral load in both urine and blood, and a renal biopsy [REF].
Tissue staining using a monoclonal antibody against MCV T antigen shows utility in differentiating Merkel cell carcinoma from other small, round cell tumors [REF].