A versatile low-temperature stopped-flow instrument compatible with both rapid and slow scanning spectrometers.
A versatile low-temperature stopped-flow instrument compatible with both rapid and slow scanning spectrometers.
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一种多功能低温停流仪器，与快速和慢速扫描光谱仪兼容。
DOI：
10.1016/0003-2697(81)90800-9
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发表时间：
1981
影响因子：
2.9
通讯作者：
Zimmer,J
中科院分区：
文献类型：
--
作者：
VanWart,HE;Zimmer,J
一种低温停流仪器已经建成，它包括一个聚四氟乙烯停流模块和一个石英观察池，被保持在一个轮廓黄铜冷却块的两个半之间。系统的温度通过泵送预冷甲醇通过冷却块中的通道来控制，并且观察池的暴露表面通过预冷干燥氮气流保持无霜。该仪器用途广泛，结构紧凑，可在−55至25°C范围内工作，在三种模式下均无泄漏或光学伪影。首先，它作为一个传统的停流仪器，使用固定波长的光来跟踪反应的进程。在第二种模式下，该仪器是接口到一个快速扫描光谱仪，使用增强的光电二极管阵列检测器和光学多通道分析仪，以获得反应中间体的时间分辨光谱。辣根过氧化物酶与过氧化氢反应期间形成的化合物I和II的吸收光谱在20.2°C下在甲醇/磷酸盐缓冲液（60/40，v/v%）中时间分辨。在第三种模式中，在−51.4°C下研究过氧化物酶反应，并使用Varian Model 219分光光度计获得中间体的吸收光谱。由于停流仪器是紧凑的，它也是与其他慢扫描实验室光谱仪的样品室兼容，它应该有利于通过其他形式的光谱反应中间体的研究。
A low-temperature stopped-flow instrument has been constructed which consists of a Teflon stopped-flow module and a quartz observation cell that are held between two halves of a contoured brass cooling block. The temperature of the system is controlled by pumping precooled methanol through channels in the cooling block, and the exposed surfaces of the observation cell are kept free of frost with a stream of precooled dry nitrogen. The instrument is versatile, compact, and can be operated over the range −55 to 25°C without leaks or optical artifacts in three modes. First, it serves as a conventional stopped-flow instrument using light of fixed wavelength to follow the progress of the reaction. In the second mode, the instrument is interfaced to a rapid scan spectrometer that uses an intensified photodiode array detector and optical multichannel analyzer to obtain time-resolved spectra of reaction intermediates. The absorption spectra of compounds I and II formed during the reaction of horseradish peroxidase with hydrogen peroxide are time-resolved at 20.2°C in methanol/phosphate buffer (60/40, v/v%). In the third mode, the peroxidase reaction is studied at −51.4°C and the absorption spectra of the intermediates are obtained with a Varian Model 219 spectrophotometer. Since the stopped-flow instrument is compact, it is also compatible with the sample compartments of other slow-scanning laboratory spectrometers and it should facilitate the study of reaction intermediates by other forms of optical spectroscopy.