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An improved technique for the cryopreservation of Onchocerca microfilariae

Published online by Cambridge University Press:  06 April 2009

P. J. Ham
Affiliation:
Department of Medical Helmintnology, London School of Hygiene and Tropical Medicine, Keppel Street (Gower Street), London WC1E 7HT
S. Townson
Affiliation:
Department of Medical Helmintnology, London School of Hygiene and Tropical Medicine, Keppel Street (Gower Street), London WC1E 7HT
E. R. James
Affiliation:
Department of Medical Helmintnology, London School of Hygiene and Tropical Medicine, Keppel Street (Gower Street), London WC1E 7HT
A. E. Bianco
Affiliation:
Department of Medical Helmintnology, London School of Hygiene and Tropical Medicine, Keppel Street (Gower Street), London WC1E 7HT

Summary

Experiments describe the use of ethanediol to store Onchocerca microfilariae in liquid nitrogen. The technique involves a 2-stage incubation of the parasites at 37 °C and 0 °C in ethanediol, before rapid cooling to − 196 °C. Viability has been assessed by motility, by migration in a proxy host and by development to the infective stage in the insect vector. A total of 71–79% of the cryopreserved microfilariae was shown to be viable compared to unfrozen controls. The technique is simple, inexpensive and very effective when compared to previous cryopreservation procedures for microfilariae and should be particularly suited for use under field conditions.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1981

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References

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