Kumamoto Yasuaki, Taguchi Atsushi, Smith Nicholas Isaac, Kawata Satoshi
Biomed Opt Express. 2011 Mar 18;2(4):927-36. doi: 10.1364/BOE.2.000927.
We employed deep UV (DUV) Raman spectroscopy for characterization of molecular photodamage in cells. 244 nm light excitation Raman spectra were measured for HeLa cells exposed to the excitation light for different durations. In the spectra obtained with the shortest exposure duration (0.25 sec at 16 µW/µm(2) irradiation), characteristic resonant Raman bands of adenine and guanine at 1483 cm(-1) and tryptophan and tyrosine at 1618 cm(-1) were clearly visible. With increasing exposure duration (up to 12.5 sec), these biomolecular Raman bands diminished, while a photoproduct Raman band at 1611 cm(-1) grew. By exponential function fitting analyses, intensities of these characteristic three bands were correlated with sample exposure duration at different intensities of excitation light. We then suggest practical excitation conditions effective for DUV Raman observation of cells without photodamage-related spectral distortion.
我们采用深紫外（DUV）拉曼光谱对细胞中的分子光损伤进行表征。对暴露于不同持续时间激发光下的HeLa细胞测量了244 nm光激发拉曼光谱。在最短暴露持续时间（16 μW/μm²辐照下0.25秒）获得的光谱中，1483 cm⁻¹处腺嘌呤和鸟嘌呤的特征共振拉曼带以及1618 cm⁻¹处色氨酸和酪氨酸的特征共振拉曼带清晰可见。随着暴露持续时间增加（最长达12.5秒），这些生物分子拉曼带减弱，而1611 cm⁻¹处的光产物拉曼带增强。通过指数函数拟合分析，这三个特征带的强度与不同激发光强度下的样品暴露持续时间相关。然后，我们提出了对细胞进行深紫外拉曼观察且无光损伤相关光谱畸变的有效实际激发条件。
