Recovery of mitochondrial DNA from blood leukocytes using detergent lysis.

Mitochondrial DNA (mtDNA) was isolated from leukocytes contained in whole blood of cattle. Leukocyte membranes except the nuclear envelope were solubilized in a buffer that contained 1% Triton X-100. After sedimentation of cell nuclei, mtDNA was purified from the cell lysate by organic solvent extraction and ethanol precipitation. Approximately 5 micrograms of mtDNA was recovered from 400 ml of whole blood, a quantity sufficient for routine DNA cloning procedures or for detailed restriction mapping studies. mtDNA isolated with this method is a suitable substrate for several DNA-modifying enzymes. Thus, preparation of mtDNA from blood by detergent lysis provides a noninvasive alternative to tissue biopsy for characterization of mitochondrial genotypes in studies of evolutionary genetics and population dynamics.