Validation and casework application of a Y chromosome specific STR multiplex.
A series of validation experiments was performed for a Y chromosome specific STR multiplex system following the suggestions made by the Technical Working Group DNA Analysis Methods (TWGDAM). The multiplex PCR products were detected on Perkin-Elmer 373 and 377 automated sequencers using two labeling colors. No problems regarding the stability, robustness and sensitivity of the Y STR multiplex were observed. Mixture studies revealed a cut off rate similar to autosomal STRs for mixtures of male DNAs and no interference of any female admixture. The comparison of the Y STR results to the autosomal typing results for 56 nonprobative semen stains and swabs, showed a slightly higher success rate in detecting the semen donor's alleles for the Y STR multiplex. Two examples are shown to illustrate the usefulness of Y STR typing for DNA mixtures. In one case the Y STR results confirmed an isolated exclusion; in the other case, the interpretation of a mixture was clarified since the Y STR results proved the presence of DNA from at least two semen donors. Y STR typing is a valuable addition to the forensic DNA testing panel.
Prinz
M
M
Office of Chief Medical Examiner, 520 First Avenue, New York, NY 10016, USA. prinzm01@popmail.med.nyu.edu
Ishii
A
A
Coleman
A
A
Baum
H J
HJ
Shaler
R C
RC
D000483:Alleles; D000818:Animals; D005260:Female; D005554:Forensic Medicine / Q000379:methods*; D006801:Humans; D015203:Reproducibility of Results; D013045:Species Specificity; D020080:Tandem Repeat Sequences; D014998:Y Chromosome / Q000235:genetics*