Université de Bordeaux, CNRS UMR 5248, Pessac, France.
Anal Bioanal Chem. 2012 Sep;404(5):1311-6. doi: 10.1007/s00216-012-6223-0. Epub 2012 Jul 20.
FTIR imaging of individual cells is still limited by the low signal-to-noise ratio obtained from analysis of such weakly absorbing organic matter when using a Globar IR source. In this study, we used FTIR imaging with a synchrotron radiation source and a focal plane array detector to determine changes in the cellular contents of cryofixed cells after culture for 48 h on Si(3)N(4) substrate. Several spectral differences were observed for cells deprived of glucose compared with control cells: a lower amide I-to-amide II ratio (P < 0.01); a different secondary structure profile of proteins (obtained from amide I spectral region curve fitting), with a significant increase in non-ordered structure components (P < 0.01); and a higher ν(C = C-H)/ν(as)(CH(3)) absorption ratio (P < 0.01), suggesting increased unsaturation of fatty acyl chains. Therefore, our study has shown that FTIR imaging with a synchrotron radiation source enables determination of several spectral changes of individual cells between two experimental conditions, which thus opens the way to cell biology studies with this vibrational spectroscopy technique.
使用 Globar 红外光源对这种弱吸收有机物质进行分析时，单个细胞的傅里叶变换红外成像仍然受到低信噪比的限制。在这项研究中，我们使用同步辐射源和焦平面阵列探测器的傅里叶变换红外成像，来确定在 Si(3)N(4)基底上培养 48 小时后，冷冻固定细胞的细胞内容物的变化。与对照细胞相比，葡萄糖缺乏的细胞表现出几种光谱差异：酰胺 I 与酰胺 II 的比值较低（P < 0.01）；蛋白质的二级结构谱图不同（通过酰胺 I 光谱区域曲线拟合获得），无序结构成分显著增加（P < 0.01）；ν(C = C-H)/ν(as)(CH(3))吸收比升高（P < 0.01），表明脂肪酸链的不饱和程度增加。因此，我们的研究表明，使用同步辐射源的傅里叶变换红外成像能够确定两个实验条件下单个细胞的几种光谱变化，从而为使用这种振动光谱技术进行细胞生物学研究开辟了道路。
