Evaluation of an automated liquid hybridization method for DNA quantitation

The AluQuant (Promega Corporation) liquid hybridization DNA quantitation method was evaluated on an automated robotic platform (Biomek 2000, Beckman Coulter, Fullerton, CA) for use in forensic PCR-STR systems. DNA from bloodstains and buccal swabs was extracted by three different methods: Chelex, Qiagen and DNA IQ (Promega). Samples were quantitated using both the Quantiblot and the AluQuant systems. Concordance between methods was determined by comparing the average AluQuant DNA concentrations for samples having matching (binned) Quantiblot values. Studies testing the "accuracy" (STR analysis), precision, sensitivity, and specifies specificity of the AluQuant method were also conducted. The effect of inhibitors (carpet, denim, and suede) was evaluated. The results indicate that the AluQuant quantitation system equals the Quantiblot system in "accuracy", sensitivity, precision, and primate-specificity. While extracts from denim and suede affected (inhibited) both systems minimally, the carpet extracts produced a sharp increase in DNA quantitation values in the AluQuant but not the Quantiblot system. The speed and user-friendliness of the AluQuant system on a robotic platform offer specific advantages to the forensic community.