HUMARA assay quality controls. HUMARA-PCR was performed on HpaII-digested (H+) and mock-digested DNA (H-) from a healthy male and analyzed by capillary gel electrophoresis, using the 3100 Genome Analyzer. Presence of a single PCR peak indicated complete DNA digestion by HpaII enzyme (A). Healthy female DNA sample (L-IV-II, upper panel) and DNA from a human monoclonal melanoma cell line (#1290, female, lower panel) were subjected to HUMARA assay. After HpaII digestion, gel (inserts) and capillary electrophoresis successfully detected a polyclonal pattern and a monoclonal pattern, respectively (B).