POLYMERASE CHAIN REACTION-BASED TECHNIQUE FOR THE DETECTION OF WUCHERERIA-BANCROFTI IN HUMAN BLOOD-SAMPLES, HYDROCELE FLUID, AND MOSQUITO VECTORS

Oligonucleotide primers were designed to amplify a 490-basepair DNA fr agment in the 5' end of the pWb 12 repeated DNA sequence in Wuchereria bancrofti for specific amplification of W. bancrofti DNA by the polym erase chain reaction (PCR). A single microfilaria in 100 mu l of blood or added to 1 ml of blood, a single third-stage larva in a pool of 20 uninfected mosquitoes, or 0.4 pg of W. bancrofti genomic DNA added to 100 mu l of human blood or serum can be detected by this PCR method. The parasite DNA in human blood and hydrocele samples and in mosquitoe s was isolated free of any PCR inhibitors using simple purification te chniques. Detection of PCR products was carried out by agarose gel ele ctrophoresis, followed by staining with ethidium bromide and visualiza tion under ultraviolet illumination. The results indicate that the PCR method is species-specific, rapid, and more sensitive than that of DN A probes and routine microscopy.