Untitled

Abstract

A quantitative PCR procedure using a newly designed primer set for ampliˆcation of human speciˆc DNA sequence D17Z1 for quantiˆcation of human DNA has been developed. The procedure was compared with the existing quantiˆcation method, UV absorption method and slot blot hybridization method. The lower limit of quantiˆcation, the reproducibility of results, quantiˆcation of degraded DNA, quantiˆcation speciˆcity and application for forensic casework samples were examined using each technique.The quantitative PCR method consumed the least amount of DNA and could quantify as little as 0.0015 ng of DNA, and its reproducibility was comparable with the UV absorption method. The STR typing of degraded DNA samples quantiˆed by slot blot hybridization method and quantitative PCR method were properly detected and typed. Since the bacterial DNA samples were not detected and quantiˆed by slot blot hybridization method and quantitative PCR method, they are useful for human-speciˆc DNA quantiˆcation of forensic evidence samples containing bacterial DNA. In the experimental application of the quantitative PCR method for various forensic casework samples, almost every STR loci were properly detected and it demonstrated a beneˆcial eŠect for actual forensic identiˆcation analysis. Furthermore, the quantitative PCR method was also useful in determining the proper amount of template DNA extracted from the sample suspected to include ampliˆcation inhibitor. In the results of the comparisons, the human speciˆc DNA quantiˆcation using the technique of quantitative PCR is more practical for forensic DNA analysis than the other methods.