Major merozoite surface protein-3β alleles identified by PCR and digestion with Pst I restriction enzymes in the Plasmodium vivax population from Bannu district, Pakistan. Lane 1 = 50 bp, 2 = 1 Kb, and 3 = 100 bp DNA marker. A, B, C = Undigested PCR products. A1, A2 ... are allele types revealed by digestion of the respective PCR products with Pst I, while M = mixed genotype. Frequencies of these alleles are presented in Table 2.