Use of a DNA hybridization assay for the detection of Plasmodium falciparum in field trials.

Journal article

A DNA probe consisting of 21 base pair repeats obtained from a Tanzanian isolate of Plasmodium falciparum, cloned in pBR322 and labeled with 32P by nick translation was used to detect malaria parasitemia in samples obtained during a malaria survey undertaken in The Gambia. In an initial trial the hybridization assay had a specificity for P. falciparum of 100% and a sensitivity of 68%. False negative results were obtained only on samples with low parasitemia. Assay of red cells collected during an earlier malaria survey which had been stored for 1 year at -20 degrees C gave a higher level of sensitivity (85%), suggesting a beneficial effect from freezing and thawing. This was confirmed by examining in the same assay red cells processed immediately after collection and after 2 weeks of storage at -20 degrees C. Freezing and thawing gave a 21% increase in positivity, and a sensitivity of 100% was achieved with the frozen samples. Quantitation of autoradiographs by visual inspection and by scintillation counting gave a reasonable correlation with parasite counts. The DNA hybridization assay has considerable promise as an epidemiological tool.

Authors: Holmberg, M; Shenton, F; Franzén, L; Janneh, K; Snow, R

• Publication status: Published
• Journal: American journal of tropical medicine and hygiene
• Volume: 37
• Issue: 2
• Pages: 230-234
• Publication date: 1987-09-01
• EISSN: 1476-1645
• ISSN: 0002-9637
• Language: English
• Keywords: Child, Preschool; Humans; Freezing; Malaria; Animals; DNA; Nucleic Acid Hybridization; Child; Blood Preservation; Plasmodium falciparum