Nucleic acids can be extracted from bone for the analysis of gene expression, to look for somatic mutations in analysis of tumors or other pathological tissue, or for genotyping archive material when other sources of DNA are not available. Several methods have been described for the extraction of DNA and RNA from tissues ( 1 – 4 ), and several kits based on these methods are currently available from biotech companies. If you are extracting DNA from a large number samples, however, it is probably cost effective to use a homemade method as described here. Successful extraction of nucleic acids from tissue is based on four procedures: disrupting the tissue so that extraction reagents can reach the cells; disrupting the cell membranes so that nucleic acids are liberated; separation of the nucleic acid from other cellular components; and precipitation and solubilization of the nucleic acid. These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.