Development of techniques for DNA-methylation analysis

• Summarizing basic determination techniques based on bisulfite treatment.
• Introducing enhanced detection methods based on biological recognition.
• Assessing advanced approaches to analysis without enzyme or bisulfite treatment.
• Summarizing development of ways to investigate and proposing perspectives.

DNA methylation is an important mode of epigenetic modification and has great significance in biochemistry, medicine and genomics. The development of techniques for DNA-methylation analysis is fundamental and pivotal for epigenome research. In around 30 years of diligent study, direct and indirect approaches were developed. Direct approaches mainly focus on global methylation analysis, while indirect approaches rely on specific recognition of DNA-methylation loci. In this review, we introduce typical methods, especially those based on developing the method of methylation-loci recognition from the most used, bisulfite conversion, biological recognition, and the newly proposed chemical cleavage. Furthermore, we assess the perspectives on the research methodology of DNA-methylation analysis. To date, there have been few summaries of the research methodology of DNA-methylation analysis. The review is envisioned to be helpful for the researchers to design novel methods of DNA-methylation analysis.