Study on the Effects of Degradation and Template Concentration on the Amplification Efficiency of the STR Miniplex Primer Sets

• NCJ Number: 241197
• Author(s): Denise T. Chung B.S.; Jiri Drabek Ph.D.; Kerry L. Opel M.A.; John M. Butler Ph.D.; Bruce R. McCord Ph.D.
• Date Published: July 2004
• Length: 8 pages
• Grant Number(s): 2002-IJ-CX-K007
• Agencies: NIJ-Sponsored
• Publication Type: Research (Applied/Empirical)
• Award: Novel STR Multiplexes with Reduced Size To Analyze DNA

Annotation

This study investigated the effects of degradation and template concentration on the amplification efficiency of the STR Miniplex primer sets.

Abstract

This study on the effects of degradation and template concentration on the amplification efficiency of the STR miniplex primer sets found that genotypes obtained from Big-Mini, Miniplex 2, and Miniplex 4 were that same with the genotypes obtained from the larger amplicons in the commercial kit. In addition, the study found that the Miniplex primer sets were able to produce complete profiles for all tested samples even for shorter template fragment lengths. The study also explored the sensitivity of 3 of the Miniplex primer sets with DNA concentrations ranging from 31 pg to 500 pg and found that two of the three primer sets were able to obtain correct genotypes at concentrations as low as 31 pg; this range of concentrations is below the range recommended for commercial sets. The primary objective of this study was to evaluate the effectiveness of a set of STR markers with redesigned primer sequences that produce smaller amplicons aimed at overcoming the problem of highly degraded forensic DNA samples obtained from crime scenes. Data for the study were obtained from analysis of enzymatically degraded DNA samples using commercially available kits and the newly developed STR Miniplex primer sets. The findings indicate that the Miniplex primer sets are capable of producing more complete DNA profiles when compared to larger amplicons obtained from the commercial kits, and that correct genotypes can be obtained with lower template concentrations than those recommended for commercial kits. These findings confirm the effectiveness of the redesigned primers at increasing the probability of obtaining a usable profile from degraded DNA samples compared to standard commercially available kits. Table, figures, and references