Comparison of five DNA quantification methods

Six commercial preparations of human genomic DNA were quantified using five quantification methods: UV spectrometry, SYBR-Green dye staining, slot blot hybridization with the probe D17Z1, Quantifiler™ Human DNA Quantification kit and RB1 rt-PCR. All methods measured higher DNA concentrations than expected based on the information by the manufacturers. UV spectrometry, SYBR-Green dye staining, slot blot and RB1 rt-PCR gave 39, 27, 11 and 12%, respectively, higher concentrations than expected based on the manufacturers’ information. The DNA preparations were quantified using the Quantifiler™ Human DNA Quantification kit in two experiments. The measured DNA concentrations with Quantifiler were 125 and 160% higher than expected based on the manufacturers’ information. When the Quantifiler™ human DNA standard (Raji cell line) was replaced by the commercial human DNA preparation G147A (Promega) to generate the DNA standard curve in the Quantifiler™ Human DNA Quantification kit, the DNA quantification results of the human DNA preparations were 31% higher than expected based on the manufacturers’ information. The results indicate a calibration problem with the Quantifiler™ human DNA standard for its use with the Quantifiler™ Human DNA Quantification kit. The possible reasons for the problem are discussed and a solution is suggested. The results emphasise the need for standard reference DNA material and standard methods for DNA quantification.