Evaluation of the Human Genomic DNA Extraction from Hair Root Method

摘要

Extraction of DNA from specimens is a required step which provides DNA for further studies in molecular genetics. In human genetic study, blood is a prefer specimen as they provide adequate DNA. However, blood specimen not always easy to collect while hair root is easier. This research is carried out to select an efficient DNA extraction method using hair root specimens. Totally 200 hair roots were collected from 20 volunteers and divided into 2 groups different in period time: fresh or 1 week, for evaluation of 2 extraction methods: phenol and salting out. The comparison will performed to evaluate the extraction method for each group based on the quantity and quality of DNA extracted. Quantity of DNA was measured by Nanodrop system. Quality of DNA was measured by the DNA on agarose gel and the product of a PCR assay. The phenol method is considered as a better method for extraction of DNA from hair root which give a higher quantity and quality of DNA. With 5 fresh hair roots, extraction by phenol method result in ＞1000ng of DNA and the average purity of DNA at 1.7, while extraction by salting out method result in about 800ng of DNA and the average purity at 1.0. Storing hair root leading to reducing the quantity of DNA extracted. PCR assay testing on DNA extracted showed the result that either salting out method or phenol method with the same amount of DNA in PCR assay they showed the successful PCR products on agarose gel. The phenol method is an efficient method for extraction of DNA from hair roots. 5 hair roots can be achieved in around 1μg of DNA which is enough for at least 10 PCR assays in human molecular genetic studies. Fresh hair root is recommended for extraction of DNA.