This article describes a set of miniSTRs capable of rapid direct PCR amplification.
There are situations in which it would be very valuable to have a DNA profile within a short time; for example, in mass disasters or airport security. In previous work, the researchers in the current project promoted reduced size STR amplicons for the analysis of degraded DNA. They also noticed that shorter amplicons are more robust during amplification, making them inhibition resistant and potentially applicable to high-speed direct PCR. In the current study, the selected markers were a subset of the Combined DNA Index System (CODIS) loci modified to permit high-speed amplification. Using the proposed protocol, the amplification of eight loci plus amelogenin directly from a saliva sample can be completed in 7 min and 38 s using a two-step PCR with 30 cycles of 98°C for 2 s and 62°C for 7 s on a Streck Philisa thermocycler. Selection of DNA polymerase, optimization of the two-step PCR cycling conditions, the primer concentrations, and the dilution of saliva are described. This method shows great potential as a quick screening method to obtain a presumptive DNA profile when time is limited, particularly when combined with high-speed separation and detection methods. (publisher abstract modified)