Investigation into the protein composition of human tear fluid using centrifugal filters and drop coating deposition Raman spectroscopy
Investigation into the protein composition of human tear fluid using centrifugal filters and drop coating deposition Raman spectroscopy
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DOI：
10.1002/jrs.2113
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发表时间：
2009-02-01
影响因子：
2.5
通讯作者：
Stone, Nicholas
中科院分区：
文献类型：
--
作者：
Filik, Jacob;Stone, Nicholas
滴涂沉积拉曼光谱(DCDRS)是一种分析弱蛋白质溶液的简单方法。这项研究是评估DCDRS泪液分析作为未来医学诊断技术的又一步。这项研究的主要目的是确定泪液样本的dCDR光谱是否包含来自不止一种蛋白质的信号(以便可以测量相对水平)，如果是的话，蛋白质是否均匀分布在沉积材料的干环中。泪液样本来自四名健康志愿者，并在分析之前汇集在一起。用离心式过滤器将蛋白质按质量分成三组。这些组包含(1)质量大于100 kDa，(2)质量在100 kDa到50 kDa之间，和(3)质量在50 kDa到3 kDa之间的蛋白质。这些蛋白质组溶液的DCDR光谱显示出显著的差异，证实了质量分离已经成功。当作为最小二乘拟合的基向量时，这些光谱(和尿素的光谱)与正常的撕裂光谱产生了很好的拟合。对单个样品上同一点的光谱和同一样品的几个液滴的光谱进行的最小二乘拟合表明，撕裂dCDR光谱具有很高的重复性。撕裂环的拉曼点图谱显示出明显的径向环变化，尤其是朝向环的外缘。环上蛋白质信号的特定峰值变化表明，外缘的差异是由于蛋白质干燥而不是不均匀的蛋白质沉积。版权所有(C)2008 John Wiley&Sons，Ltd.
Drop coating deposition Raman spectroscopy (DCDRS) is a simple method of analysing weak protein solutions. This study is another step in evaluating the analysis of tear fluid by DCDRS as a future medical diagnostic technique. The main aims of this study are to determine whether the DCDR spectra from tear samples contain signals from more than one protein (so relative levels can be measured) and, if so, are the proteins homogeneously distributed in the dried ring of the deposited material. Tear samples were collected from four healthy volunteers and pooled prior to analysis. Proteins were separated by mass into three groups using centrifugal filters. These groups contained proteins with (1) masses greater than 100 kDa, (2) masses between 100 and 50 kDa and (3) masses between 50 and 3 kDa. DCDR spectra from each of these protein group solutions displayed significant differences, confirming that the mass separation had been successful. When used as basis vectors for least-squares fitting, these spectra (and that of urea) produced excellent fits to the normal tear spectra. Least-squares fitting of spectra from the same point on a single sample and from several drops of the same sample showed that the tear DCDR spectra were highly reproducible. Raman point mapping of the tear ring showed significant radial ring variation, especially towards the outer edge of the ring. The specific peak changes in the protein signal across the ring suggested that the difference in the outer edge was due to protein desiccation as opposed to inhomogeneous protein deposition. Copyright (C) 2008 John Wiley & Sons, Ltd.