A simple method for extraction and purification of genomic DNA from dried blood spots on filter paper.

We have developed an efficient and simple method for extracting and purifying genomic DNA from dried blood stored on filter paper. The quality of the genomic DNA extracted is tested by PCR amplification of a 255-bp fragment of the PAX8 gene sequence and the PCR products are determined for further genetic studies by single strand conformation polymorphism (SSCP) analysis. Larger DNA sequences of the 674-bp of the PAX8 gene and the 1,039-bp of the human beta-globin gene, a housekeeping gene, have also been amplified from the extracted DNA, thus indicating the high quality of the genomic DNA extracted by the developed method for subsequent genetic studies of any gene of interest. The method developed can also be used for the purification of genomic DNA from dried blood specimens stored under different conditions. Moreover, the genomic DNA products can be stored for long-term use due to the highly purified procedure. Therefore, the method is efficient and appropriate for the extraction and purification of genomic DNA from dried blood specimens, which has become an increasingly important tool for genetic and epidemiological studies.