Abstract 3768: Optimization of digital pathology through laser capture microdissection with a 405 nm laser

Abstract

Abstract Tumor cellular heterogeneity is a complex problem in cancer molecular diagnostics and personalized therapy. The tumor is a product of the different types and interactions of host and immune cells. Investigators have created a variety of methods to procure separate subpopulations of the tumor microenvironment for individual analysis. One of the most successful methods of this is laser capture microdissection (LCM). This method captures specific subpopulations of cells under direct microscopic visualization. This LCM technology has successfully been used for over 20 years, revealing a variety of insights into cancer pathogenesis and mechanisms of therapeutic response employed in numerous clinical trials. Nevertheless, there are two drawbacks to the current systems. For UV cutting (365 nm), the tissue is significantly damaged by the UV light energy. Infrared (808 nm) laser systems do not damage the tissue however, this method has low power and poor resolution. Our first hypothesis to be tested is that a new class of near UV 405 nm laser will have small capture areas approaching single cells while simultaneously preventing cellular damage. The second weakness of LCM is the requirement for an open-faced tissue section without a coverslip. Moreover, when visualizing the tissue of interest, the identification of regions of interest is obscured due to the refractive index mismatch between the laser microdissection cap and the tissue surface. We hypothesize that using a volatile organic compound with a refractive index similar to glass would elucidate the tissue region of interest to allow proper visualization. We successfully developed and tested a near 405 nm wavelength LCM system that utilizes a “liquid” coverslip to visualize the sample of interest with higher clarity, resolution, and contrast for immunohistochemistry, immuno-fluorescence, blood smear slides, and conventional hematoxylin-eosin tissue staining. Overall, these critical improvements LCM technology now allow for single-cell tissue capture, system automation, tissue visualization, and opens the door for artificial intelligence-assisted spatial profiling. Citation Format: Thomas Philipson, Marissa Howard, Kevin Johnson, Amanda Still, Furkat Yunusov, Emanuel Petricoin, Virginia Espina, Noel Gonzalez, Alan Carpino, Lance Liotta. Optimization of digital pathology through laser capture microdissection with a 405 nm laser [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3768.