SDS-PAGE of recombinant P. vivax CSP (rPvCSP) and its immunoblot reacted with human sera. The size of the rPvCSP was 30 kDa and was estimated by comparison with known molecular weight standards (A). Purified rPvCSP was separated by SDS-PAGE under reducing condition and electroblotted onto PVDF membrane (B). The blot was blocked and reacted with Penta-His antibody, VK210 typed patient serum samples from ROK adults (numbered samples) or VK247 typed patient serum from Thailand (ks580, ms992, ms999, ms1231 and ms1308); P. falciparum infected patient serum from Uganda (U6, U19, U23 and U34) and sera from vivax naïve individuals in ROK (Neg-1, Neg-2, Neg-3 and Neg-4) as negative control. T: total translation mix; FT: flow through; E: elusion; M: molecular mass marker.