Improvement in labeling efficiency of hydrophilic and hydrophobic fluorescent molecules in thick tissue sections

Abstract

In this work, we investigated the labeling efficiency of hydrophilic and hydrophobic fluorescent probes DAPI and Nile Red in porcine liver slices. We performed uni- and bi-directional diffusion on porcine liver tissue sections on the order of a few hundred microns in thickness and we found that bi-directional diffusion significantly enhanced the penetration of probe diffusion efficiency. Although diffusion mostly accurately describe labeling process, we did find that after the removal of the labeling molecules, residual probe molecules in the tissue sections continue to transport in labeling additional tissue constituents. Our study shows that bi-directional labeling can significantly enhance the labeling of thick tissues for applications in which structural information in three-dimensions is needed.