Abstract

Raman spectroscopy provides a comprehensive molecular information of a biological sample without any invasive and destructive treatment prior to a measurement. An imaging modality by Raman spectroscopy, namely spontaneous Raman microscopy, is an unreplaceable tool for label-free molecular imaging and analysis of cells and tissues [1.2]. However, the slow measurement speed limits application of spontaneous Raman microscopy to high-speed and high-resolution imaging. Here I present acceleration of spontaneous Raman microscopy in biomedical applications. Multiplexed spatial sampling accelerates spontaneous Raman imaging. Multiline illumination Raman microscopy uses multiple line-shaped laser foci in scanning a sample, improving the imaging speed by 4 orders of magnitude in comparison to conventional confocal Raman microscopy [3]. With 21-line illumination, it is finished in 11.4 min to acquire 800 × 1,312 pixels hyperspectral Raman image of mouse brain tissue. Other results obtained by multiline illumination Raman microscopy will also be presented. In comparison to conventional confocal Raman microscopy, multiline illumination Raman microscopy has a disadvantage in the detectable wavenumber region with one exposure. However, Raman imaging does not always require a wide spectrum range. It has been demonstrated that cell and tissue classifications, such as cancer diagnosis and peripheral nerve detection, can be performed using only limited bands in a Raman spectrum [4,5]. I will discuss the potential new applications of Raman spectroscopic imaging in life sciences by multiline illumination Raman microscopy.

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