Tissue Clearing / Imaging

Introduction

The first Tissue Clearing Technique was reported more than 100 years ago; however, breakthrough techniques have been reported in the last decade with the advanced techniques of fluorescence microscopes. Many Japanese researchers are developing a variety of approaches for Tissue Clearing to get a better view of the circuitry. We have a lineup of the techniques from Japan according to various samples and applications.

Principle

The light is scattered on its path through the biological tissue due to the presence of various substances with different refractive indexes (RI) in the tissues. Therefore, to make the biological tissue transparent, it is necessary to remove the high RI component from the tissue, replace the solvent with a high refractive index liquid, or incorporate both to make the RI in the tissue uniform.

When observing the clarified sample, if the immersion liquid of the microscope and the clarifying solution have different RI (particularly for objects with a high numerical aperture: NA), spherical aberration will occur and hinder deep observation. For an object with a correction ring, you need to use an objective lens with an immersion liquid that is as close as possible to the RI of the clearing solution and rotate the correction ring to correct spherical aberration. Deep and high-resolution observations are possible by using an objective lens that matches the RI of each transparent technology.

The general protocol for tissue clearing with FUJIFILM Wako products follows the guideline shown below: