The method of extracting DNA from bones is mainly used for ancient remains and forensic examination. This process needs to be carried out very carefully and the following steps are common<\/p>\n\n\n\n
Bone DNA extraction is usually performed from relatively well preserved bone. The bone site chosen is generally a hard site (e.g. femur or tooth).This increases the likelihood of good DNA preservation.<\/p>\n\n\n\n
It is important to clean the bone surface as the sample may be contaminated from external sources. This involves a process of scraping or cleaning the bone surface to remove external tissue and contaminants. Scraping the surface usually removes external contaminants.<\/p>\n\n\n\n
To extract the DNA, the bones are ground into a fine powder. This is done using a specialized grinder or mill. Crushing the bone makes it easier to access the inner tissue of the bone, which contains DNA.<\/p>\n\n\n\n
Bone contains high levels of calcium, which must be removed in order to extract DNA. In the demineralization process, bone powder is soaked in an acidic solution (e.g. EDTA solution) to dissolve and remove the calcium. This facilitates the extraction of organic components (i.e. DNA) from the bone.<\/p>\n\n\n\n
After demineralization, a common DNA extraction protocol is used to extract DNA. This is a process in which the bone powder is soaked in lysis buffer (a solution that destroys cells and releases DNA) to elute the DNA. Phenol-chloroform extraction or commercial DNA extraction kits are then used to recover the DNA in solution.<\/p>\n\n\n\n
Extracted DNA may contain proteins and other impurities. To remove these impurities, the DNA is purified. Ethanol precipitation and silica-based columns are common methods of purification.<\/p>\n\n\n\n