NCJ Number
241299
Date Published
June 2012
Length
61 pages
Annotation
Using a combination of novel methods for selectively improving male DNA fractions, this study demonstrates how to obtain male donor profiles collected 6 to 9 days after intercourse.
Abstract
This is a significant improvement in the time frame in which male profiles can be successfully recovered from post-coital samples. In an attempt to increase the recovered amount of input male DNA available for Y-STR amplifications, the use of DNA extraction concentration and purification was evaluated. The concentration of an entire extract into 10 - 12 ml resulted in the amplification of the entire DNA in the original extracts. Using this approach, partial Y-STR profiles were recovered from 6-day post-coital samples. This proved to be the first component of a strategy for increasing the post-coital interval from which DNA profiles can be recovered. A novel Y-chromosome specific nested PCR pre-amplification multiplex was designed to produce sufficient quantities of template male DNA prior to subsequent Y-STR amplifications. Validation of this pre-amplification multiplex demonstrated that full Y-STR profiles could be obtained from as little as 5 - 10 pg of input male DNA. The use of the pre-amplification multiplex in combination with extract purification/concentration resulted in a significant improvement in the time frame in which male DNA profiles could be recovered. Y-STR profiles were obtained from samples collected up to 9 days after intercourse. Currently, the researchers are attempting to develop a pre-amplification multiplex for use with the miniUHD system, so as to improve sensitivity. This system could be used in combination with the Yfiler multiplex in order to increase the discriminatory power afforded by standard Y-STR typing. Researchers are currently involved in a collaborative study to test a larger number of 4-, 7-, 9-day post-coital samples with approximately 100 donor couples, using enhanced profiling techniques. 3 tables, 10 figures, 30 references, and a listing of publications and presentations of the study findings