A New Procedure for the Multiplex PCR Amplification of TH01, CSF1PO and TPOX Loci with Small Amplicon Lengths.

Abstract

We describe a new procedure for the multiplex PCR ampliˆcation of the three short tandem repeat (STR) loci; TH01, CSF1PO and TPOX with small amplicon lengths (the Small TCT Multiplex). The accuracy of the Small TCT Multiplex was veriˆed by typing 100 Japanese samples that had been previously typed using an AmpFlSTR Green I PCR ampliˆcation kit (Green I Kit). The results using the Small TCT Multiplex were consistent with those obtained by the Green I Kit. STR typing using the Small TCT Multiplex was examined from 36 bloodstain samples that had been left for 1 to 25 years at room temperature and compared to that using the Green I Kit. The Small TCT Multiplex was superior to the Green I Kit for STR typing especially in the case of bloodstain samples that had aged for more than 8 years.

A Comparison of DNA Extraction Using AutoMate Express™ and EZ1 Advanced XL from Liquid Blood, Bloodstains, and Semen Stains

“…The 2‐year‐old bloodstains all gave full profiles with good quality in all the extraction conditions. As the bloodstains got older, peaks at STR loci with large amplicons >250 bp tended to become lower or disappear because of DNA degradation and full STR profiles were difficult to obtain. However, the AutoMate Express™ and the EZ1 Advanced XL with half‐diluted G2 buffer showed the same number of full and partial profiles from 8‐ and 14‐year‐old bloodstains (Table ).…”

“…However, at present, we have no plans to change the lysis conditions for the EZ1 Advanced XL, because these changes did not work well for aged bloodstains and aged semen stains. We think that the lysis conditions should be optimized for aged stains, from which full STR profiles are more difficult to obtain than from fresh stains .…”