An improved temperature-jump apparatus

✍ Scribed by A.S. Verkman; A.A. Pandiscio; M. Jennings; A.K. Solomon

• Publisher: Elsevier Science
• Year: 1980
• Tongue: English
• Weight: 552 KB
• Volume: 102
• Category: Article
• ISSN: 0003-2697
• DOI: 10.1016/0003-2697(80)90337-1

✦ Synopsis

A temperature-jump device of the type devised by M. Eigen (1954, Discuss. Furaduy Sot. 17, 194-210) was built using an 8000-to 40,000-V capacitor discharge to raise the temperature of a conductive sample as much as 25°C within 5 ps. The temperature-jump cell design, which differs from that of previously built cells, consists of cylindrical electrodes fitted into a quartz cylindrical observation cell. This allowed for variable electrode spacing and eliminated high-voltage arcing as well as the need to degas samples to prevent solution cavitation. The temperature of a 0.3-to 3.0-ml sample volume could be adjusted over a -20 to 60°C temperature range by circulating 20% glycerol in water through the hollow, stainless-steel electrodes. Absorption, fluorescence, and scattering measurements could be made over the wavelength range 220 to 750 nm with signal to noise ratios generally exceeding 1000: 1. A battery-driven, high-intensity mercury arc lamp provided stable. ripple-free light. The optical signal was amplified, digitized by a waveform recorder, transferred to a computer, and analyzed numerically to resolve multipleexponential decay processes. The performance of this apparatus is illustrated by several membrane-substrate interactions.