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

Key words: forensic genetics, extraction, exfoliated epithelial cell