This project sought a DNA typing system that overcomes the limitations of samples found at crime scenes.
The project replicated the DNA sample, i.e., synthesized new DNA from existing DNA to obtain sufficient quantities for analysis and then identified genetic markers for DNA typing. This procedure, known as PCR-STR, can produce reliable results with degraded specimens, is quick, and can be automated to permit the creation of a vastly improved database of DNA profiles of convicted offenders. STR analysis was initially developed as a manual process, but automated methods are becoming available. The key to this technology is the use of fluorescent chemicals during the PCR process. A laser-generated fluorescent signal from the STR alleles passes information to a computer, where the collected data are analyzed to produce DNA profile information. In addition, robotic workstations are available to process DNA samples and assist with other procedures. With automation, the entire process, from DNA extraction to data interpretation, could be accomplished with little human involvement or manipulation, thereby reducing the possibility of error. PCR-STR promises to extend the application of DNA typing as a powerful criminal justice tool that helps to establish, with a high degree of certitude, the guilt or innocence of suspects. 3 notes
Date Published: February 1, 1997