Abstract: Objective To establish a 15-plex rapid STR multiplex amplification system. Methods Fourteen auto-chromosome loci and one sex-chromosome were selected to compare the situations of allelic losses and nonspecific amplication under different conditions. FastStart Taq DNA polymerase and DNA standard sample 9947A were used during amplification and optimization process.15-plex rapid STR amplification system was achieved by performing various experiments including selection of amplification conditions and the volume of DNA polymerase, adjustment of inter-locus balance, optimization of rapid amplification, screening of reaction buffers, selection of reaction volume, and a variety of additives. Results Using 10 μL rapid PCR system, including 1 ng DNA templates, 0.4 μL polymerase and 10×FastStart high fidelity reaction buffer, a complete and well-balance DNA profile of 15 STR loci for standard genomic DNA was obtained in 32 minutes, without the allele drop-out and non-specific amplicons. Meanwhile, 5% glycerinum, 0.01% gelatin, 0.05% gelatin and 5 mmol/L ammonium sulfate could be used as the reactive additive during the amplification procedure. Conclusion The 15-plex rapid STR multiplex amplification system can be used to decrease reaction time and enhance sample throughput.

Key words: forensic genetics, short tandem repeat, polymerase chain reaction, system establishment