Short report: A practical technique for the cryopreservation of Dirofilaria immitis, Brugia malayi, and Wuchereria bancrofti microfilariae

A technique to cryopreserve microfilariae has been developed. This method was used to cryopreserve microfilariae of Dirofilaria immitis, Brugia malayi, and Wuchereria bancrofti at a controlled rate of 1 degree C/min by use of a freezing tank. Microfilariae of each of these species retained their ability to infect susceptible mosquito species and develop to the infective stage after cryopreservation. The method presented here is quickly and easily carried out with inexpensive equipment.