Abstract
Three-dimensional microscopy of large biological samples (>0.5 cm3) is transforming biological research. Many existing techniques require trade-offs between image resolution and sample size, require clearing or use optical sectioning. These factors complicate the implementation of large volume 3D imaging. Here we present Multi-fluorescent High Resolution Episcopic Microscopy (MF-HREM) which allows 3D imaging of large samples without the need for clearing or optical sectioning.
MF-HREM uses serial-sectioning and block-facing wide-field fluorescence, without the need for tissue clearing or optical sectioning. We detail developments in sample processing including stain penetration, resin embedding and imaging. In addition, we describe image post-processing methods needed to segment and further quantify these data. Finally, we demonstrate the wide applicability of MF-HREM by: 1) quantifying adult mouse glomeruli. 2) identifying injected cells and vascular networks in tumour xenograft models; 3) quantifying vascular networks and white matter track orientation in mouse brain.