THE VALIDATION OF SHORT TANDEM REPEAT (STR) LOCI FOR USE IN FORENSIC CASEWORK

A quadruplex reaction has been developed which amplifies the short tan dem repeat (STR) loci HUMVWA31/A, HUMTHO1, HUMF13A1 and HUMFES/FPS. De tection of the PCR products employs denaturing polyacrylamide gels cou pled with fluorescent-based technology. This system has been evaluated for use in rotine forensic casework and has been shown to be both rob ust and reproducible. The quadruplex reaction is as sensitive as the c ommercially avialable HLA DQalpha Amplitype typing system and can be u sed on both degarded and aged material. The problems of environmental contamination have been shown to be limited provided strict procedural practices are followed - i.e. physical separation of sample extractio n and amplified products; the use of dedicated equipment such as pipet tes; the separation of amplification preparation area. The ability of the system to detect mixtures and the successful analysis of case stai ns has shown that this system is well suited as a tool for forensic in vestigation.