Quantitation of Human Genomic DNA Through Amplification of the Amelogenin Locus

An alternate method for quantitation of human genomic DNA is presented. Quantitative template amplification technology (abbreviated “Q‐TAT”) estimates the quantity of human DNA present in an extract by comparing fluorescence in X and Y amplicons produced from unknowns with fluorescence in a standard curve amplified from known quantities of reference DNA. Q‐TAT utilizes PCR and electrophoresis with fluorescent detection/quantitation, precluding the need for new instrumentation, methodology, or quality assurance associated with slot‐blot or real‐time PCR. In a comparison study incorporating shared samples, Q‐TAT was found to be more sensitive than widely used slot‐blot methods but somewhat less sensitive than real‐time PCR. Among samples containing DNA concentrations ranging from 100 pg/μL to 2–4 ng/μL, Q‐TAT produced DNA concentration estimates that agreed reasonably well with either Quantiblot® or real‐time PCR. Q‐TAT was reproducible with a typical coincidence of variation of about 35%. Quantitation of human DNA in this study involved summing fluorescence in X and Y amplicons in unknowns and quantitation standards. However, analyzing fluorescence in X and Y amplicons individually could allow estimates of male and female DNA present in mixtures to be made. Moreover, since X and Y amplicons exhibit sizes of 210 and 216 bp, respectively, the integrity as well as the concentration of the genomic DNA template can be assessed. Q‐TAT represents an alternate method useful for the quantitation of human genomic DNA prior to amplification of STR loci used for identity testing purposes. The method uses existing equipment and procedures in conjunction with a well‐characterized DNA standard to produce concentration estimates for unknowns that reliably produce STR profiles suitable for analysis.