Grasping the actions of the molecules and cells that constitute our bodies is essential for the progress of medicine. This has resulted in a persistent effort for clear visuals of what occurs beyond human perception. In a study recently released in Science Advances, researchers from Osaka University have unveiled a technique that produces high-resolution Raman microscopy images.
Raman microscopy serves as an effective method for visualizing biological specimens as it can furnish chemical details regarding specific molecules—such as proteins—that are involved in the body’s functions. Nonetheless, the Raman light emitted from biological samples is notably faint, which often results in the signal being overwhelmed by background noise, yielding subpar images.
The research team has engineered a microscope capable of retaining the temperature of previously frozen samples throughout the acquisition process. This innovation has enabled them to generate images that are as much as eight times more luminous than those previously recorded using Raman microscopy.
A significant factor leading to indistinct images is the movement of the subjects being observed. By imaging frozen samples that were immobilized, we could utilize extended exposure durations without harming the specimens. This resulted in elevated signals relative to the background, enhanced resolution, and broader fields of view.”
Kenta Mizushima, lead author of the study
The method employs no dyes and does not rely on any chemicals to immobilize the cells, thus can offer a highly accurate representation of processes and cellular actions.
The team was additionally able to verify that the freezing technique preserved the physicochemical conditions of various proteins. This grants the cryofixing method a unique edge in achieving what chemical fixing methods cannot accomplish.
“Raman microscopy provides a supplemental option to the imaging arsenal,” notes senior author Katsumasa Fujita. “The capability to not only deliver cellular images but also information regarding the distribution and specific chemical states of molecules is immensely beneficial as we constantly aim for the most thorough understanding possible.”
The novel technique can be integrated with other microscopy modalities for comprehensive examination of biological specimens and is anticipated to enhance a broad spectrum of fields in the biological sciences, including medicine and pharmaceuticals.
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Journal reference:
Mizushima, K., et al. (2024). Raman microscopy of cryofixed biological specimens for high-resolution and high-sensitivity chemical imaging. Science Advances. doi.org/10.1126/sciadv.adn0110.