[Study on detection of malaria parasite DNA by PCR-ELISA].

AIM To present a new malaria diagnostic method based on detection of malaria parasite DNA by PCR-ELISA. METHODS According to the conserved sequence of Plasmodium SSUrRNA genes reported, a pair of primers in which one primer was biotinylated and another was unbiotinylated, suitable for DNA amplification of both falciparum and vivax malaria parasites were designed and synthesized. After denaturation and washing, the incorporated biotinylated product with avidin coated on plates previously was hybridized with the fluorescein-labelled oligonucleotide probes specific for Plasmodium falciparum or Plasmodium vivax. The color developed after adding POD conjugated with antibody to fluorescein and substrate can be semi-quantitated spectrophotometrically. RESULTS The thresholds of parasite density for the detection of Plasmodium falciparum and Plasmodium vivax by this test were shown to be as low as 4 and 10 parasites per microliter of blood, respectively and no cross reaction was seen in the detection of falciparum and vivax malaria parasites. CONCLUSION With promising sensitivity and specificity, this test can be used in malaria survey.