In the present study a new DNA extraction method is described. The new protocol, which uses caprylic acid for isolating DNA, is technically simple and very fast, as it enables us to obtain DNA from peripheral blood in only 10 minutes. Moreover, DNA preparations obtained with this procedure can be effectively used for HLA class II and variable number tandem repeat genotyping by polymerase chain reaction, so the new method is well suited for routine clinical use in any type of analysis requiring DNA typing for individual characterization.