ISSN:
1550-7408
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Biology
Notes:
SUMMARY. The addition of 1.0–1.1 M (9–10%) glycerol to CPLM medium of Johnson and Trussell permits Tritrichomonas foetus to survive when frozen slowly to -20d̀ or -76d̀C. and stored at either temperature. After freezing to -76d̀C. at the rate of 1d̀C. per minute, 38% of the protozoa were alive after 1 day, and some survived more than 128 days. After freezing to -20d̀C. in 1–2 hours, 63% of the protozoa were alive after 1 day, 46% after 8 days, and some survived 32 to more than 128 days in different experiments. After freezing to -20d̀C. in about 7 hours, 68% were alive after 1 day, 36% after 8 days, and some survived 16 to more than 64 days in different experiments. A concentration of 0.55 M (5%) glycerol is about as effective as 1.1 M, but 0.14 and 0.28 M are much less effective. If the protozoa are snap-frozen to -76d̀C., glycerol does not protect them, nor do they survive slow freezing without glycerol. In CPLM medium containing 1.0 M ethylene glycol, 72% of the protozoa were alive 1 day after having been frozen to -20d̀C. in about 7 hours, 29% were alive after 8 days, and some survived from 16 to more than 32 days in different experiments. The above figures are averages. In parallel tests at a concentration of 1.0 M in CPLM medium following slow freezing to -20d̀C. and storage at that temperature for 1 day, ethylene glycol was 80–90% as effective as glycerol; 1,2,3,4-butanetetrol was 67% as effective; 1,2-propanediol was 57% as effective; 2,3-butanediol, 14%; mannose, 6%; and mannitol, 1%. Glycerol monoacetate and polyvinyl alcohol were inactive; and 2,3-dimercaptopropanol was toxic.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1550-7408.1955.tb02409.x
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