Amplified product length polymorphism (APLP): a novel strategy for genotyping the ABO blood group.

We present a simple rapid reproducible polymerase chain reaction based technique, termed amplified product length polymorphism (APLP), as a new strategy for primer design for ABO genotyping. The method involves the use of primers differing in length and permits the identification of the major ABO genotypes (A1, A2, B, OA, OG, and O2) according to the molecular size of the allele-specific amplified products. Ten different primers designed to analyze the variations in nucleotide positions 261, 297, 796, 802, and 1059-1061 of cDNA are mixed in one reaction, and the amplified products are resolved on a polyacrylamide gel. Of eight PCR fragments (132 bp, 120 bp, 108 bp, 98 bp, 88 bp, 80 bp, 72 bp, and 64 bp), two to five are amplified in the reaction according to ABO genotypes. The new technique has been successfully applied to the genotyping of 221 peripheral blood samples from Japanese and Germans whose ABO phenotypes had previously been determined; a novel A allele (AG) was found in Japanese individuals.