Storage conditions and stability of global DNA methylation in placental tissue. (June 2013)

• Record Type: Journal Article
• Authors: Vilahur, Nadia; Baccarelli, Andrea A; Bustamante, Mariona; Agramunt, Silvia; Byun, Hyang-Min; Fernandez, Mariana F; Sunyer, Jordi; Estivill, Xavier
• Is Part Of: Epigenomics. Volume 5:Number 3(2013)
• Page Start: 341
• Page End: 348
• Publication Date: 2013-06
• Subjects: cohort study -- DNA methylation stability -- luminometric methylation assay -- placenta -- pyrosequencing -- variability; Epigenesis -- Periodicals; Genomics -- Periodicals; Chromatin -- Periodicals; DNA -- Periodicals; 572.87
• DOI: 10.2217/epi.13.29
• Languages: English
• ISSNs: 1750-1911

Abstract

Aim: The placenta is an informative and easily available tissue for many epidemiological studies. We analyzed the extent to which storage delay affects DNA methylation.Material & methods: Biopsies from two placentas were sequentially stored at -80°C after standing at room temperature for 30 min, 1 h, 2 h, 6 h and 24 h. Global DNA methylation was measured by bisulfite pyrosequencing of repetitive elements and the luminometric methylation assay.Results: Small changes in global DNA methylation in relation to time-to-storage were observed by pyrosequencing, with a coefficient of variation (COV) of 2.49% (placenta 1) and 2.86% (placenta 2), similar to the mean technical variation observed for pyrosequencing (COV: 1.91 and 1.51%, respectively). A luminometric methylation assay yielded more variable results in the two placentas analyzed, both among time points (COV: 9.13 and 10.35%, respectively) and technical replicates (COV: 11.60 and 9.80%, respectively).Conclusion: Global DNA methylation is stable at room temperature. However, some techniques to measure methylation might be confounded by DNA degradation caused by a delay in storage.