Tetrahydrofuran and Dichloromethane Delipidation of a Whole Mouse Brain v1

Organic solvent strategies for whole-brain delipidation involve dehydrating the tissue in a water-miscible solvent followed by washes with a water-immiscible solvent. Tissue shrinkage will occur, but when paired an aqueous delipidation step and expansion chemistry becomes negligible. Additionally, an extensive dehydration gradient is used to preserve tissue morphology. We use tetrahydrofuran (THF) as the dehydration solvent, which helps permeabilize cell membranes. THF is then transitioned into dichloromethane as the main delipidation solvent. This protocol produces a delipidated whole brain that can be further processed for expansion or index-matched for immediate imaging.