Sample Preparation Correlative XPCT – Histology

This protocol describes a workflow for preparing biological tissue samples for **correlative X-ray phase-contrast tomography (XPCT)** and **histological analysis**. The method enables nondestructive 3D imaging of structural features prior to conventional sectioning, allowing direct correlation between volumetric XPCT data and high-resolution microscopy. Tissue samples are first fixed to preserve morphology and then embedded in paraffin. Following XPCT scanning, samples are carefully retrieved, processed through dehydration and embedding, and subsequently sectioned for routine histology or immunohistochemistry. By maintaining consistent orientation and minimizing deformation throughout processing, corresponding regions can be reliably matched between XPCT volumes and histological sections. This correlative approach is particularly valuable for studying complex biological structures, enabling visualization of their 3D organization and subsequent molecular characterization within the same specimen. The protocol supports applications in neurodegeneration research, developmental biology, and other fields requiring integrated multiscale imaging.