Methods for Typing the STR Triplex CSF1PO, TPOX, and HUMTHO1 That Enable Compatibility Among DNA Typing Laboratories

Abstract

Typing polymorphic loci at the DNA level has become a routine procedure in the paternity and identity testing fields. Originally, highly polymorphic variable number of tandem repeats (VNTR) loci were characterized by restriction fragment length polymorphism (RFLP) analysis (Wyman and White 1980; Jeffreys et al. 1985a; Jeffreys et al. 1985b). A subgroup of these VNTR loci is the short tandem repeats (STR) loci. These loci are highly polymorphic and are abundant in the human genome (Edwards et al. 1991; Edwards et al. 1992). The STR loci are composed of tandemly repeated sequences of 2–7 base pairs in length. Because the allele size of STRs is generally less than 350 base pairs, they are amenable to amplification by the polymerase chain reaction (PCR) (Saiki et al. 1985; Edwards et al. 1991). Therefore, STRs can be typed with a high degree of specificity and sensitivity, in a relatively short time period, and without the need for isotopic detection methods. Moreover, the amplified products of STRs can be resolved at least to a single repeat unit by separation on denatured Polyacrylamide gels (Edwards et al. 1991; Hochmeister et al 1995; Huang et al. 1995).