A Modified Protocol for Bisulfite Genomic Sequencing of Difficult Samples

<p>Abstract</p> <p>The bisulfite genomic sequencing protocol is a widely used method for analyzing DNA methylation. It relies on the deamination of unmethylated cytosine residues to uracil; however, its high rates of DNA degradation and incomplete cytosine to uracil conversion ofte...

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Bibliographic Details
Main Authors: Toulouse Andr&#233;, Pappas Jane, Bradley WEC
Format: Article
Language:English
Published: BMC 2009-01-01
Series:Biological Procedures Online
Subjects:
Online Access:http://www.biologicalproceduresonline.com/content/11/1/99
Description
Summary:<p>Abstract</p> <p>The bisulfite genomic sequencing protocol is a widely used method for analyzing DNA methylation. It relies on the deamination of unmethylated cytosine residues to uracil; however, its high rates of DNA degradation and incomplete cytosine to uracil conversion often lead to failed experiments, uninformative results, and false positives. Here, we report the addition of a single-step multiple restriction enzyme digestion (MRED) designed to differentially digest polymerase chain reaction products amplified from unconverted DNA while leaving those of converted DNA intact. We show that for our model system, <it>RARB2</it> P2 promoter, use of MRED increased informative sequencings ninefold, and MRED did not alter the clonal representation in one fully methylated cell line, H-596, treated or not with 5-azadeoxycytidine, a methylation inhibitor. We believe that this method may easily be adapted for analyzing other genes and provide guidelines for selecting the most appropriate MRED restriction enzymes.</p>
ISSN:1480-9222