ABSTRACT
Objective To successfully get the full PCR alleles of the Insertion/Deletion marker rs10644346 in which a SNP-binding exists at the 3'end region of the primer.Methods Based on the AS-PCR,a common forward primer and two reverse primers with allele-specific oligonucleotides at the last second 3'end instead of the terminus were tentatively designed for typing 150 unrelated individuals and 10 father-mother--child trios from Htnan province in South-central China.Simultaneously,9 samples were typed with all the above three primers (the two primer sets which consist of the common forward primer and one of the reverse primers).Results PCR amplicons were well detected in the 150 unrelated individuals after being typed with the three primers,and the amplified fragments of parental and filial generations among 10 father-mother-child trios conformed to Mendel's principles.Allele missing was found in the two-primer group.Conclusion The primers designed by locating the specific nucleotide at the last second 3'end rather than terminal position were demonstrated also effective in getting specific alleles if perfect mismatch and PCR conditions are guaranteed,and the design strategy can provide an optional reference to rescue markers of SNP-binding primers for forensic practice.