The influence of substrate on DNA transfer and extraction efficiency

The propensity for the same nine substrates to impact upon the efficiency of DNA extraction procedures was also examined. Significant (p = 0.03) differences were found among the extraction efficiencies from different materials. When 15 μL of blood was deposited on each of the substrates, the lowest quantity of DNA was extracted from plastic (20 ng) and the highest quantities extracted from calico and flannelette (650 ng). Significant (p < 0.05) differences also exist among the DNA extraction yield from different initial blood volumes from all substrates. Also, significantly greater (p < 0.05) loss of DNA was seen during concentration of extracts with higher compared to lower initial quantities of DNA. These findings suggest that the efficiency of extraction and concentration impacts upon the final amount of DNA available for analysis and that consideration of these effects should not be ignored. The application of correction factors to adjust for any variation among extraction and concentration efficiencies among substrates is proposed.