Validation of the STR system FXIIIB for forensic purposes in an Austrian population sample

The short tandem repeat system FXIIIB was amplified by the polymerase chain reaction (PCR) on blood samples from 201 unrelated Austrians and analyzed by horizontal, non-denaturing polyacrylamide gel electrophoresis. The mean exclusion chance was 0.496, the discriminating power 0.883 and the heterozygosity rate 78.61%. In 50 families (100 meioses) no mutations were found. Sufficient amplification could be achieved with as little as 80 pg of high molecular weight cell line DNA, which could be reduced to 60 pg by using 32 instead of 30 cycles. By reamplifying 1 microliter for another 15 cycles, the threshold could be reduced to less than 20 pg. Nevertheless this sensitivity was only possible with cell line DNA, since reamplification of simulated stains proved to be problematical due to artifacts. In a degradation experiment. DNA extracted from bloodstains stored for up to 26 days in a moist chamber and DNA boiled for up to 18 min could be amplified. A quadruplex PCR with VWA, FES and amelogenin is proposed.