Storage conditions and stability of global DNA methylation in placental tissue

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...

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Bibliographic Details
Authors: Vilahur Chiaraviglio, Nadia, 1982-; Baccarelli, Andrea A.; Bustamante Pineda, Mariona; Agramunt, Silvia; Byun, Hyang-Min; Fernandez, Mariana F.; Sunyer Deu, Jordi; Estivill, Xavier, 1955-
Format: Article
Status:Accepted version
Publication date:2013
Country:España
Institution:Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
Repository:Recercat. Dipósit de la Recerca de Catalunya
OAI Identifier:oai:recercat.cat:10230/36592
Online Access:http://hdl.handle.net/10230/36592
http://dx.doi.org/10.2217/epi.13.29
Access Level:Open access
Keyword:ADN -- Metabolisme
ADN -- Metilació
Placenta -- Metabolisme
Description
Summary: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.