A simple protocol for DNA extraction from feace of the giant panda and lesser panda

摘要

We developed a new method to extract DNA from faecal samples in this study. Fresh faecal samples of the giant panda and lesser panda were collected and stored in 100% ethanol. About 200–300 mg faecal samples were collected in a microcentrifuge tube through repeated centrifugation then washed by ethanol and sterile water. Faecal samples were lysed rapidly with 1% SDS and centrifuged quickly, then transferred the supernatant to a new tube. DNA was extracted using Chloroform/Phenol after incubation with Proteinase K, following by precipitation and purification. Mitochondrial DNA control region, cytochrome b and 12 S rRNA gene were amplified and sequenced successfully from faecal DNA, suggesting that the methods of sample storage and DNA extraction were reliable and efficient. This method not only overcame previous barriers to molecular scatology, such as inhibitors, low quality and degradation of DNA, but also was more economical than commercial kits (e.g. QIAamp DNA Stool Mini Kit ， Qiagen). We monitored some background faecal DNA and discussed potential risks from background DNA contamination, such as genomes of bacteria, virus, parasites and prey. No negative effect was observed during amplification and sequencing of target DNA, which showed that background DNA had no effect on genetic study of target animals [ Acta Zoologica Sinica 50 (3): 452 - 458, 2004].