Assessment of the quality and quantity of genomic DNA recovered from canine blood samples by three different extraction methods

The ideal method for genomic DNA (gDNA) extraction should recover high quantities of pure, integral gDNA from the original sample source with minimal co-extraction of inhibitors of downstream processes. Canine ethylenediamine tetra-acetic acid (EDTA) treated and clotted blood samples were extracted by three different methods (a silica column method, a phenol–chloroform method and a modified salt precipitation method). Phenol–chloroform and modified salt precipitation based extractions demonstrated similar relative recovery of gDNA with EDTA preserved blood, but were less efficient at recovering gDNA from clotted blood. Spectrophotometer measurement of phenol–chloroform based extractions tended to overestimate the quantity of gDNA recovered from extractions, and was associated with the greater co-extraction of PCR inhibitors. The silica column method recovered gDNA with equal efficiency, purity and integrity irrespective of the sample type or method of quantification.