单个血小板的拉曼光谱分析

利用波长为785 nm的激光束构建光镊拉曼光谱系统，俘获悬浮在生理盐水中的人和三种动物(家猪、大鼠、家兔)的单个血小板，激发并收集其拉曼光谱。单个血小板的平均拉曼光谱信号清楚地反映了血小板的生化组成特点，人血小板的拉曼光谱与三种动物的明显不同，1 524 cm-1是人类血小板所特有的拉曼信号峰，而1 157 cm-1在人类中显著高于三种动物的，人类血小板的平均I_{1 157}/ I_{1 003}为0.795，而家猪、大鼠、家兔的分别为0.532，0.502，0.485。多元统计分析结果显示，不同物种血小板的拉曼信号落入不同的空间，可以判别区分。上述结果表明，单个血小板的拉曼光谱基本反映了血小板的主要组成成分，结合多元统计分析可以用于辨别不同的物种的血小板，光镊拉曼光谱系统是实时研究细胞生理、生化变化的快速简便而有效的工具。

Raman Micro-Spectroscopy of Single Blood Platelets

The authors collected the Raman spectra of single blood platelets of human,pig, rat and rabbit suspended in saline solution by using a laser tweezers Raman spectroscopy(LTRS) setup.A single platelet cell was trapped in the focus of a near-infrared laser beam at 785 nm and the excited Raman spectrum was acquired.For each species,the Raman spectra of up to 20 platelet cells were acquired and were used to perform a principal components analysis(PCA) or a discriminate function analysis(DFA).The average Raman spectra indicate that the vibration bands at 1 524 and 1 157 cm-1 of human platelets are obviously different from those of the platelets from pig,rat and rabbit.The Raman intensities at 1 157 and 1 524 cm-1 bands are significantly high for human platelets. The ratio I1 157/I1 003 of human platelets was 0.795,but those of pig,rat and rabbit were 0.532,0.502 and 0.485,respectively.In addition,the platelets from four different species can be discriminated with multivariate analysis.These findings demonstrate that the LTRS,combined with multivariate analysis,could be used to rapidly discriminate platelets from various species and may find valuable application in rapid sensing of biochemical changes in a single cell.