Successful cryopreservation of Wuchereria bancrofti microfilariae.

A fast freezing technique developed by James (1981) significantly improved the yield of schistosome larvae that could be stored in liquid nitrogen. This was adapted by Ham et al. (1981) to the freezing of microfilariae of Onchocerca spp. with excellent results. They found 70 to 80% of the cryopreserved larvae remained viable using this method and since then Ham (personal communication) has successfully applied the same technique to Brugia malayi microfilariae. The further application to Wuchereria bancrofti is described.