Centre for Atomic and Molecular Physics, Manipal University, Manipal, India.
PLoS One. 2010 Apr 29;5(4):e10427. doi: 10.1371/journal.pone.0010427.
An optical trap has been combined with a Raman spectrometer to make high-resolution measurements of Raman spectra of optically-immobilized, single, live red (RBC) and white blood cells (WBC) under physiological conditions. Tightly-focused, near infrared wavelength light (1064 nm) is utilized for trapping of single cells and 785 nm light is used for Raman excitation at low levels of incident power (few mW). Raman spectra of RBC recorded using this high-sensitivity, dual-wavelength apparatus has enabled identification of several additional lines; the hitherto-unreported lines originate purely from hemoglobin molecules. Raman spectra of single granulocytes and lymphocytes are interpreted on the basis of standard protein and nucleic acid vibrational spectroscopy data. The richness of the measured spectrum illustrates that Raman studies of live cells in suspension are more informative than conventional micro-Raman studies where the cells are chemically bound to a glass cover slip.
一种光学陷阱与拉曼光谱仪相结合，在生理条件下对经光固定的、单个、活的红色（RBC）和白细胞（WBC）的拉曼光谱进行高分辨率测量。利用强聚焦的近红外波长光（1064nm）来捕获单个细胞，而 785nm 光则用于在低入射功率（几毫瓦）下进行拉曼激发。使用这种高灵敏度、双波长仪器记录的 RBC 拉曼光谱能够识别出几个附加谱线；迄今未报道的谱线纯粹源自血红蛋白分子。根据标准蛋白质和核酸振动光谱数据，对单个粒细胞和淋巴细胞的拉曼光谱进行了解释。所测量光谱的丰富性表明，悬浮液中活细胞的拉曼研究比传统的微拉曼研究更具信息量，在传统的微拉曼研究中，细胞被化学结合到玻璃载玻片上。
