Luleå University of Technology, Department of Computer Science and Electrical Engineering, 971 87 Luleå, Sweden.
Analyst. 2009 Sep;134(9):1815-21. doi: 10.1039/b820931f. Epub 2009 Jul 7.
Most Raman spectroscopic studies on tissue are performed in vitro. To assure that the results are applicable to in vivo examinations, preparation protocols and measurement procedures of tissue for in vitro studies should preserve tissue characteristics close to the native state. This study had two aims. The first was to elucidate if photoinduced effects arise during 5 minutes' continuous illumination of tissue with an 830 nm laser at an irradiance of approximately 3 x 10(10) W/m2. The second was to investigate the effects of snap-freezing of porcine prostate tissue in liquid nitrogen and subsequent storage at -80 degrees C, by means of multivariate analysis. 830 nm laser illumination of the specified irradiance did not affect the Raman spectra. A decrease of the spectral background was observed, likely due to photobleaching of tissue fluorophores. Snap-freezing and subsequent storage at -80 degrees C gave rise to subtle but significant alterations in Raman spectra, most likely related to changes in the protein conformations.
大多数组织的拉曼光谱研究都是在体外进行的。为了确保研究结果适用于体内检查，体外研究中组织的制备方案和测量程序应尽可能保持组织的天然状态。本研究有两个目的。第一个目的是阐明在 830nm 激光持续照射组织 5 分钟的过程中，是否会产生光诱导效应，激光的辐照度约为 3 x 10(10) W/m2。第二个目的是通过多元分析研究猪前列腺组织在液氮中快速冷冻和随后在-80°C 下储存的影响。在指定辐照度下用 830nm 激光照射不会影响拉曼光谱。观察到光谱背景的减少，这可能是由于组织荧光团的光漂白。快速冷冻和随后在-80°C 下储存会引起拉曼光谱的细微但显著的变化，这很可能与蛋白质构象的变化有关。
