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Automated STR Analysis for DNA Databases

NCJ Number
Mark W. Perlin Ph.D.
Date Published
December 2002
20 pages
This document focuses on the validation of automated short tandem repeat (STR) analyses of DNA databases.
STR technology has enabled the rapid generation of DNA data for use in human identification. These data must be carefully analyzed. There is now an acute shortage of skilled data reviewers. The original STR data are carefully reviewed by two or more people to minimize error. To alleviate the critical labor shortage, the TrueAllele expert system was developed. The computer program automates virtually every human review function and provides consistent quality assessment and allele designation. The TrueAllele process begins with automated input of the data. The second step is automated gel image or capillary signal analysis. Step three is the allelic analysis, where the computer begins by analyzing the allelic ladders, transforming the data into DNA length coordinates and then accurately quantitating every DNA event in the data. In the final output step, TrueAllele automatically exports the data in format suitable for automated database import. A concordance validation study was conducted of the TrueAllele expert system for DNA database applications. Over 48,000 genotypes were processed using diverse STR panels and automated DNA sequences. It was demonstrated that the automated analysis and quality assurance system was accurate and that it could reduce the human time, error, effort, and costs associated with conventional labor-intensive review of Combined DNA Index System (CODIS) data. The automated methods were objective and comprehensive, providing for more uniform application of DNA forensic technology. 4 figures, 4 tables, 9 references