A modified bisulfite conversion method for the detection of DNA methylation

Aim: Our purpose is to improve the conventional procedures for bisulfite conversion used to detect 5-methylcytosine in DNA. Methods: Impacts of different bisulfite salts, bisulfite conversion temperature, antioxidants and denaturants on DNA conversion and degradation were assessed by methylation-sensitive melt curve analysis. The modified method was tested on different genes and the conversion efficiency was analyzed by bisulfite sequencing. Results: We developed a modified bisulfite conversion method that completes this process within 2 h. We demonstrate that high temperature denaturation is the major cause for DNA degradation, and the addition of ethylene glycol dimethyl ether is an effective way to accelerate the bisulfite conversion. The conversion efficiency is comparable to many other commercial kits. Conclusion: Our modified bisulfite conversion method is simple, cost efficient and less time consuming and is compatible with different genes and samples, thus has a great potential for the future research and clinical applications.