The maintenance of free-living amoebae by cryopreservation

Original Article


Korean J Parasitol. 1992 Jun;30(2):151-153. English. Published online Mar 20, 1994. http://dx.doi.org/10.3347/kjp.1992.30.2.151
Copyright © 1992 by The Korean Society for Parasitology


The maintenance of free-living amoebae by cryopreservation
S A Seo,T S Yong and K Im
Department of Parasitology College of Medicine & Institute of Tropical Medicine, Yonsei University, Seoul 120-752, Korea.


Abstract
We have successfully cryopreserved free-living amoebae in order to maintain them feasibly under the conditions in our laboratory. The viability of trophozoites was higher when frozen by slow cooling (overall 0.7℃/min) than by fast cooling (overall 1.3℃/min). Glycerol and dimethylsulfoxide at the final concentration of 7.5% each was used for cryopreservation of free-living amoebae trophozoites. The survival rate was 2-39% after storage in the liquid nitrogen for 60 days. Gross cultural or morphological changes were not noted in trophozoites thawed from frozen suspensions.

Figures


	Fig. 1 The comparison of cooling rate.


	Fig. 2 The recoveries after storage in the liquid nitrogen. The initial suspension of amoevae contained 2×10⁶ trophozoites/ampoule.

Tables


	Table 1 The comparison of survival rates (%) in the case of 2.5×10⁶ of Naegleria fowleri and Acanthamoeba culbertsoni trophozoites by means of fast cooling and slow cooling

References


1.	Cohen LM, Eveland LK. Cryopreservation of Schistosoma mansoni sporocysts. J Parasitol 1984;70(4):592.

2.	Cooper LA, Lewis FA, File-Emperador S. Re-establishing a life cycle of Schistosoma mansoni from cryopreserved larvae. J Parasitol 1989;75(3):353–356.

3.	Dwyer DM, et al. J Parasitol 1971;57(1):190–191.

4.	James ER. Cryopreservation of helminths. Parasitol Today 1985;1(5):134–139.

5.	Lumsden WH, Robertson DH, McNeillage GJ. Isolation, cultivation, low temperature preservation, and infectivity titration of Trichomonas vaginalis. Br J Vener Dis 1966;42(3):145–154.

6.	Moril T, Matsui T, Iijima T, Abe N, Yoshizawa A, Chikatsune M, Watanabe M. Cryopreservation of Leucocytozoon caulleryi sporozoites. J Protozool 1988;35(3):356–359.

7.	Neal RA, Latter VS, Richards WH. Survival of Entamoeba and related amoebae at low temperature-II. Viability of amoebae and cysts stored in liquid nitrogen. Int J Parasitol 1974;4(4):353–360.

8.	Raether W, Uphoff M. Survival of monoxenically (Crithidia sp.) and axenically grown Entamoeba histolytica cultures after storage in liquid nitrogen. Int J Parasitol 1976;6(2):121–125.

9.	Rossi P, Pozio E. Cryopreservation of Trichinella newborn larvae. J Parasitol 1988;74(3):510–511.

*10.*	Simione FP Jr, Daggett PM. Freeze preservation of pathogenic and nonpathogenic Naegleria species. J Parasitol 1976;62(1):49.

*11.*	Willaert E. Ann Soc Belge Med Trop 1971;51:701–708.