Using Evans Blue Dye to Determine Blood‐Brain Barrier Integrity in Rodents

The blood-brain barrier (BBB) is an active and selective barrier that shields the brain from endogenous and exogenous insults. Different stimuli may lead to the disruption of this barrier, including inflammation and trauma. Several methods are used to evaluate BBB disruption. The most widely used method is Evans blue (EB) dye extravasation. EB cannot normally pass through the BBB and thus its presence in brain tissue indicates alterations in permeability. This protocol details the steps of EB extravasation in rodents. Important aspects regarding critical steps and advantages are also provided. © 2019 by John Wiley & Sons, Inc.