Storage conditions and stability of global DNA methylation in placental tissue

Nadia Vilahur, Andrea A. Baccarelli, Mariona Bustamante, Silvia Agramunt, Hyang Min Byun, Mariana F. Fernandez, Jordi Sunyer, Xavier P. Estivill

Research output: Contribution to journalArticle

18 Citations (Scopus)


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.

Original languageEnglish
Pages (from-to)341-348
Number of pages8
Issue number3
Publication statusPublished - Jun 2013
Externally publishedYes



  • cohort study
  • DNA methylation stability
  • luminometric methylation assay
  • placenta
  • pyrosequencing
  • variability

ASJC Scopus subject areas

  • Genetics
  • Cancer Research

Cite this

Vilahur, N., Baccarelli, A. A., Bustamante, M., Agramunt, S., Byun, H. M., Fernandez, M. F., Sunyer, J., & Estivill, X. P. (2013). Storage conditions and stability of global DNA methylation in placental tissue. Epigenomics, 5(3), 341-348.