Current Trends in Cryobiology
During the past 20 years there have been amazing developments in low temperature physics, engineering, and biology. They form part of the very rapid post-war growth in pure and applied sciences of every kind. During this period several branches of biology
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THE INTERNATIONAL CRYOGENICS MONOGRAPH SERIES General Editors
Dr. K. Mendelssohn, F. R. S. The Clarendon Laboratory Oxford, England Dr. K. D. Timmerhaus University of Colorado Boulder, Colorado
H. J. Goldsmid
Thermoelectric Refrigeration, 1964 G. T. Meaden Electrical Resistance of Metals, 1965 E. S. R. Gopal Specific Heats at Low Temperatures, 1966 M. G. Zabetakis Safety with Cryogenic Fluids, 1967 D. H. Parkinson and B. E. Mulhall The Generation of High Magnetic Fields, 1967 W. E. Keller Helium-3 and Helium-4, 1969 A. J. Croft Cryogenic Laboratory Equipment, 1970 A. U. Smith Current Trends in Cryobiology, 1970
CURRENT TRENDS IN CRYOBIOLOGY Edited by Audrey U. Smith Clinical Research Centre National Institute for Medical Research Mill Hill, London, England
99 >99
80 (10 in 0·85 % NaCl) 80-90 80-90 90 40 >99 2-5 60-65 85 >99 >99
Per cent survival after freezing and thawing: cells suspended in M/15 phosphate buffer, pH 6·8
no change no change no change
increase in slope increase in slope increase in slope reduction of shoulder abolition of shoulder abolition of shoulder increase in slope abolition of shoulder increase in slope increase in slope increase in slope
1·0 0·85 1·00
7·0 5·0 5·5 5'2 5·0 2·5 7·0 3·5 8·5 2·5 2·0
Enhancement factor: ratio of doses producing 90 % inactivation at Change in survival curve 22 and -79°C
Supersensitivity of Microorganisms and Transforming DNA to the Inactivating Action of Ultraviolet in the Frozen State [After Ashwood-Smith et al. (25)]
Table 3
!....
("'l
~
21
Microorganisms, Plants, and Insects 106 , -_ _ _ _ _ _ _ _ _ _,
10'
Micrococcus radiodurans
Ne E
.. J
';;;-~
subtilis (spores) 10 3
102
~, 0
"SO
"100
"ISO "200
Irradiation temperature
Fig. 4. Comparison of sensitivities to ultraviolet radiation and the effect of temperature on these sensitivities. [After Ashwood-Smith et al. ("7).] 0 - - 0 Micrococcus radiodurans; . - - . Bacillus subtilis (spores); A--A E. coli WP2.
'c
Notes to Table 3 1. Two very closely related strains of A. aerogenes were used apparently identical in all growth and biochemical characters excepting that one strain gave rise to rough (r) colonies as opposed to smooth (s).
2. Pseudomonas sp. is fairly sensitive to freezing and thawing in the presence of phosphate buffer in that survival is rarely better than 5 %. 3. Hill, R. F. and Rossi, H. H., Radiation Res., 1, 282 (1954); AshwoodSmith, M. J., Bridges, B. A., and Munson, R. J., Science (N. Y.), 149, 1103 (1965). 4. Levine, M. and Cox, E., Radiation Res., 18, 213 (1963).
5. M. radiodurans was included in the general survey of low-temperature ultraviolet sensitivity as it has been shown to be very resistant to both ultraviolet irradiation (Duggan, D. E., Anderson, A. W., Elliker, P. R., and Cain, R. F., Food Res. 24, 376 (1959) and X-radiation (Anderson, A. W., Nordon, H. c., Cain, R. F., Parrish, G. and Duggan, D., Food Technol., 10, 575 (1956). When subjected to freezing and thawing more than 95 % of the viable units (which are usually tetrads) survived. 6. Deoxyribonu
