| Abstract [eng] |
Optical microscopy is widely used in medicine for imaging of biological tissues. Imaging of histological H&E-stained sections with a brightfield microscope is used in high-throughput / primary stage clinical imaging, while confocal microscopy in combination with special fluorescent dyes is used for detailed imaging of tissues, cells, and their components. Nonlinear optical microscopy provides additional contrast and new information about biological structures. One of such structures is collagen, which is investigated for applications in cancer diagnostics. Different contrasts of biological tissues can be obtained using nonlinear imaging modes of MPF, SHG and THG. Although these nonlinear optical modalities have long been known, there is not much information about THG nonlinear microscopy and the origin of this signal. As a result, it was decided to develop a nonlinear optical scanning microscope and use it to study MPF, SHG and THG images obtained from histological sections in order to elucidate the nature of THG in collagen. The results showed that collagen, which is a major component of the extracellular matrix, can be visualized in THG mode due to hematoxylin and eosin dyes. Both dyes generate THG signal individually and in conjunction. Eosin provides the highest THG signal intensity from the extracellular matrix. Also, THG imaging provides good contrast between cell nuclei and the extracellular matrix, and provides additional information about the collagen structure. Because H&E samples are prepared for standard pathological testing, imaging using THG mode does not require additional sample preparation and can be used in cancer diagnosis. |
