Platelet contamination causes large variation as well as overestimation of mitochondrial DNA content of peripheral blood mononuclear cells

• Published in: Annals of clinical biochemistry 2008-09, Vol.45 (5), p.513-514
• Main Authors: Urata, Michiyo, Koga-Wada, Yui, Kayamori, Yuzo, Kang, Dongchon
• Format: Article
• Language: English
• Subjects: Biomarkers - metabolism; Blood Platelets - cytology; Blood Platelets - metabolism; Chemistry, Clinical - methods; DNA, Mitochondrial - metabolism; Humans; Leukocytes - metabolism; Leukocytes, Mononuclear - cytology; Leukocytes, Mononuclear - metabolism; Platelet Count; Reproducibility of Results; Reverse Transcriptase Polymerase Chain Reaction
• ISSN: 0004-5632; 1758-1001
• DOI: 10.1258/acb.2008.008008

Background Alterations in the copy number of mitochondrial DNA (mtDNA) play a role in the pathogenesis of mitochondrial diseases and other many common diseases. Recently, the copy number of leukocyte mtDNA has been considered to serve as a biomarker to monitor or chase such diseases. Therefore, reproducible mtDNA measurement is required. Methods Peripheral blood mononuclear cells were prepared by a density-based method. The mtDNA/cell was measured by quantitative realtime polymerase chain reaction. Results The degree of platelet contamination varied to a large extent among preparations. The mtDNA copy numbers per mononuclear cell were 269 ± 51 and 146 ± 14 in the samples before and after the platelet depletion, respectively. Conclusion A density-based mononuclear cell preparation causes heavy platelet contamination. The platelet depletion from a sample is particularly important for comparing the mtDNA contents between different dates or between different patients.