Abstract: To find a simple, rapid, reliable and effective method for ancient DNA extraction. Methods Four methods based on silica particles and silica-based spin columns(A:Modified Silica Particles Method;B:Geneclean Method;C:QIAamp Mothod;D:Modified QIAquick Method) were respectively used to extract mitochondrial DNA (mtDNA) from 5 ancient sheep dated to 4 000 years ago. PCR amplification of mtDNA was performed, and its results were evaluated by agarose gel electrophoresis. The effects of 4 kinds of methods mentioned above were determined by examining amplification success rates of DNA from 5 ancient sheep. Results The amplification success rates of 4 methods were different from 20% to 100%, and the effects of extraction based on silica-based spin columns (60%, 100%) were distinctly better than those based on silica particles (20%, 40%). The effect of extraction based on modified silica particles was the worst, and based on modified QIAquick was the best among 4 methods. Conclusion Modified QIAquick Method is a highly effective method, with a 100% success rate, in which Centricon○[KG-*4/5]〖WT7”〗R ultrafiltration devices are used to concentrate teeth digest solution and purify DNA through silica-based spin columns. It can effectively remove the inhibitor as well as obtain preferable DNA template.

Key words: DNA extraction, silica particles, silica-based spin columns