Check samples for laboratory self‐assessment in DNA flow cytometry. The national cancer institute's flow cytometry network experience

• Published in: Cancer 1989-04, Vol.63 (8), p.1592-1599
• Main Authors: Coon, John S., Deitch, Arline D., de Vere White, Ralph W., Koss, Leopold G., Melamed, Myron R., Reeder, Jay E., Weinstein, Ronald S., Wersto, Robert P., Wheeless, Leon L.
• Format: Article
• Language: English
• Subjects: Analytical biochemistry: general aspects, technics, instrumentation; Analytical, structural and metabolic biochemistry; Biological and medical sciences; Cell Count; Cell Separation; DNA, Neoplasm - analysis; Fixatives; Flow Cytometry - standards; Fundamental and applied biological sciences. Psychology; Humans; Interinstitutional Relations; National Institutes of Health (U.S.); Quality Control; Reference Standards; Specimen Handling - methods; Tissue Preservation - methods; Tumor Cells, Cultured; United States; Urinary Bladder Neoplasms - genetics; Urinary Bladder Neoplasms - pathology
• ISSN: 0008-543X; 1097-0142
• DOI: 10.1002/1097-0142(19890415)63:8<1592::AID-CNCR2820630825>3.0.CO;2-G

The National Cancer Institute's Flow Cytometry Network (NCI‐FCN) is attempting to facilitate the transfer of flow cytometry (FCM) of exfoliated bladder cells from the research laboratory to the clinical laboratory. Demonstrating interinstitutional consistency in FCM analysis of replicate specimens simulating clinical barbotage specimens, fixed to allow easy transporation and storage at room temperature was one specific objective. Simulated barbotage specimens were prepared by mixing cultured aneuploid bladder carcinoma cells with normal or mitogen‐stimulated peripheral blood mononuclear cells in different ratios. The samples were fixed in 10% formalin for 30 minutes, stored in buffer, and enucleated with pepsin, pH 1.5, before staining with propidium iodide for FCM DNA analysis. Preservation in ethanol or other common DNA cytochemcal reagents was found to be unsatisfactory. In contrast, the formalin‐fixed samples showed excellent preservation of quantitative DNA fluorescence and coefficient of variation of histogram peaks for over 2 weeks. Exchange of eight fixed specimens among five network laboratories that analyzed them as “unknowns” showed good overall agreement on histogram data and interpretation, although some noteworthy interlaboratory differences were found. This technique could be used for self‐assessment surveys of clinical laboratory performance in DNA FCM of bladder barbotage specimens.