No cross-binding reactions applying new Plasmodium vivax forward primer in modified species-specific 18S PCR . The original Plasmodium vivax primer from a multiplex PCR  cross-bonded with Plasmodium falciparum when applied in the modified species-specific 18S PCR . The new Plasmodium vivax (Pv) primer was cross tested against different Plasmodium falciparum (Pf) patient samples with diverse levels of high parasitaemia. The results showed on a 2% agarose gel. Lane 1 = 100 bp DNA Ladder, lanes 2-6 = Five different positive Pv patient samples, lane 7 = 2% Pf, lane 8 = 2-3% Pf, lane 9 = 7% Pf, lane 10 = 7-10% Pf, lane 11 = 10-15% Pf, lane 12 = 20% Pf, and lane 13 = No template. The product size of Pv is 241 bp.