出版社：International Medical Journal Management and Indexing System
摘要：Abstract Objective: To develop a method to enhance the sensitivity of current multiplex STR DNA profiling without (i) increasing the number of PCR cycles, or (ii) developing an entirely new multiplex. This has been accomplished by using a kit that (a) concentrates and (b) purifies all of the generated PCR amplicons from current commercially available multiplex kits such that the efficiency of capillary electrophoresis electrokinetic injection is dramatically increased and a signal boost of up to twenty fold (20X) can be achieved. Methods: The developed kit was initially tested using known positive controls diluted to mimic low template PCR reactions. In addition to these reproducible laboratory-generated examples, real world low level DNA samples derived from processing individual latent ridge impressions identified with powders (i.e., fingerprints) were also evaluated. Commercial DNA-STR kits from Applied Biosystems and Promega were both tested as were DNA profile mixtures from two contributors. Final electropherograms and DNA profiles before and after post-PCR clean-up with AmpliconRx were compared. Results: In all samples tested, both laboratory and forensic, AmpliconRx treatment of post-PCR samples provided at least a 5-10 fold boost in electrophoretic peak heights, i.e., a 5-10 fold increase in RFU signal for all alleles. No changes in peak balance were observed for either single source or mixed samples; the increased signal was true to the original electrophoresis. Additional typed peaks could be recovered from low level DNA samples using AmpliconRx. Conclusions: Amplicon Rx can recover alleles that are present in the original low template PCR sample, but are invisible when current protocols, which analyze only 5% of PCR reaction, are used for capillary electrophoresis. This method can successfully and efficiently recover useful, probative data from low level samples.
关键词：forensic sciences; forensic genetic; post-PCR processing; DNA typing; low template DNA
