A simple procedure was developed for spotting blood samples directly onto nylon membrane filter, without the necessity to treat samples with pronase or proteinase K, followed by hybridizing with 32P-labelled DNA probe, pUNK1-45. This probe detected specifically P. falciparum DNA and did not cross react with DNA from man, P. knowlesi, P. chabaudi or P. cynomolgi. The probe was sensitive to detect a parasitemia of 0.001% in 20 microliters of blood.