[The application of three methods combined for extracting DNA from human epithelium].

To improve DNA extraction from human epithelium. Chelex-100, Chelex-100 organic combined and Chelex-100 magnetism pearl combined methods were adopted according to the situation of each case. With the stepwise extracting protocol, the trace amount of DNA was analyzed most efficiently and the success rate of DNA extracting was better improved. The efficiency of DNA extraction from human epithelium could be greatly improved by modifying the extracting protocol such as purification and concentration based on previous results.