Krishna C Murali, Sockalingum G D, Venteo L, Bhat Rani A, Kushtagi Pralhad, Pluot M, Manfait M
Center for Laser Spectroscopy, Manipal Academy of Higher Education, Manipal 576104, India.
Biopolymers. 2005 Dec 5;79(5):269-76. doi: 10.1002/bip.20346.
A pilot Raman microspectroscopy study of formalin-fixed, paraffin-embedded, and deparaffinized sections from the same ovarian normal and malignant tissues was carried out. This approach was considered in order to evaluate the suitability of these ex vivo tissue handling procedures in discrimination as well as biochemical characterization. The spectra of formalin-fixed normal and malignant tissues exhibited no contamination due to formalin, which is indicated by the absence of strong formalin peaks; spectral features also show significant differences for normal and malignant tissues. The differences between spectral profiles of deparaffinized normal and malignant tissues are subtle and spectra show few residual sharp peaks of paraffin. Complete dominance of paraffin swamping signals from tissues was observed in the spectra of paraffin-embedded tissues. Principal components analysis (PCA), which was employed for discrimination of tissue type, provided good discrimination for formalin-fixed and paraffin-embedded tissue spectra. PCA of deparaffinized tissues resulted in a poor classification with significant overlap among the clusters. Thus, this study indicates that formalin fixation is the most suitable among the three procedures employed in the study. Significant differences between spectral profiles of normal and malignant formalin-fixed tissues can not only be exploited for discrimination but can also provide information on biochemical characteristics of the tissues. Deparaffinized tissues provide poor discrimination and information on tissue biochemistry is lost. Paraffin-embedded tissues may provide good discrimination, but predominance of paraffin in the spectra could jeopardize biochemical characterization. Prospectively, as a result of the better availability of paraffin-embedded tissues and problems associated with frozen sectioning of formalin-fixed tissues, the results of this study using paraffin-embedded tissues are very encouraging.
对来自相同卵巢正常组织和恶性组织的福尔马林固定、石蜡包埋及脱蜡切片进行了一项拉曼显微光谱初步研究。考虑采用这种方法是为了评估这些离体组织处理程序在鉴别以及生化特征分析方面的适用性。福尔马林固定的正常组织和恶性组织的光谱未显示出因福尔马林导致的污染，这由没有强烈的福尔马林峰表明；光谱特征也显示正常组织和恶性组织之间存在显著差异。脱蜡后的正常组织和恶性组织光谱轮廓之间的差异很细微，且光谱显示石蜡的残留尖峰很少。在石蜡包埋组织的光谱中观察到石蜡信号完全淹没了组织信号。用于鉴别组织类型的主成分分析（PCA）对福尔马林固定和石蜡包埋的组织光谱提供了良好的鉴别效果。脱蜡组织的PCA导致分类效果不佳，各聚类之间有明显重叠。因此，本研究表明，在该研究采用的三种程序中，福尔马林固定是最合适的。福尔马林固定的正常组织和恶性组织光谱轮廓之间的显著差异不仅可用于鉴别，还能提供有关组织生化特征的信息。脱蜡组织提供的鉴别效果不佳，且有关组织生物化学的信息丢失。石蜡包埋组织可能提供良好的鉴别效果，但光谱中石蜡占主导可能会危及生化特征分析。前瞻性地看，由于石蜡包埋组织更容易获得，以及与福尔马林固定组织冷冻切片相关的问题，本研究使用石蜡包埋组织的结果非常令人鼓舞。
