Evaluation of a Synthetic Oligonucleotide Probe for Diagnosis of Plasmodium falciparum Infections

Abstract

A radiolabeled synthetic oligonucleotide was evaluated as a diagnostic probe specific for Plasmodium falciparum using blood samples lysed directly on nitrocellulose filters. The probe technique successfully diagnosed malaria in experimentally infected chimpanzees that had 0.001% parasitemias (50 parasites/µl) as determined by blood smears, and in 1 chimpanzee whose blood smear was negative, but whose blood was culture-positive for P. falciparum. In a double blind study of 50 patient samples from the Philippines, the probe results correlated well with blood smear results when the autoradiographs were read after 4–8 hr exposure. The results indicate that the oligonucleotide probe may be useful in the rapid and specific diagnosis of P. falciparum infection.