ISSN:
1059-910X
Keywords:
Phosphatidylcholine
;
Docosane
;
Kinetics
;
Phase transitions
;
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Natural Sciences in General
Notes:
We describe a temperature-jump device that permits time-resolved studies of thin cryo-transmission electron microscopy specimens. The specimen is rapidly heated to induce a change in microstructure just prior to cryo-fixation. The apparatus consists of a xenon arc lamp equipped with a shutter controlled by timing circuitry, used in conjunction with an environmental specimen preparation chamber. The specimen is heated by exposure to focused light from the lamp, and then plunged into cryogen. Using a thermocouple constructed from an electron microscope grid, we show that temperature jumps of 30-60 K are achieved with exposure times of 150-450 milliseconds. Micrographs of dimyristoyl phosphatidylcholine (DMPC) vesicles and n-docosane films, subjected to these exposures, shew that the specimens are still at least 20-30 K above their initial temperature when they contact the cryogen. This method could be applied to a variety of biological and chemical systems which undergo structural changes activated by a rise in temperature.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jemt.1070200110
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