Abstract 2293: A fast and simple method for whole-genome bisulfite library preparation from ultra-low DNA inputs

The distribution of 5-methylcytosine (5-mC) in DNA within the eukaryotic genome is known to greatly affect gene regulation and is currently a major topic of research. Studies on DNA methylation have been aided by advancements in bisulfite conversion and Next-Gen sequencing technologies which can provide single-base resolution of 5-mC across the entire genome. Many whole-genome bisulfite sequencing (WGBS) library preparation protocols designed for analysis of 5-mC distribution employ bisulfite to chemically convert unmethylated cytosine bases into uracil following the library preparation step. While these protocols produce reliable results, degradation of DNA is always an inherent issue when dealing with bisulfite conversion, and a large proportion of the adapterized library is often fragmented and can no longer be amplified. This requires high levels of DNA to serve as the input material. However, by rearranging the order of library preparation and bisulfite conversion, we developed a streamlined protocol that necessitates less input material for accurate whole-genome methylation analysis at single-base resolution. This unique workflow accommodates picogram quantities of starting material, making it ideal for analysis of precious samples that are of limited availability (e.g., FFPE). Comparison of sequencing data generated using this new library preparation method and data generated with established Reduced Representation Bisulfite Sequencing demonstrated a correlation of 0.95 in CpG sites with > 10X coverage in human DNA. Also, with only slight modification, this protocol is versatile enough to be used in the preparation of libraries for ChIP-Seq and RNA-Seq analyses. Citation Format: Karolyn Giang, TzuHung Chung, Xueguang Sun, Marc E. Van Eden, Xi Yu Jia. A fast and simple method for whole-genome bisulfite library preparation from ultra-low DNA inputs. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2293. doi:10.1158/1538-7445.AM2014-2293