This is my first try to do Clarity with 2M mouse whole brain. The brain sample was perfused and fixed with 4% PFA. So I incubated brain sample with Hydrogel solution in dark room for 2 weeks on a rotator. After polymerization and washing, I did electrophoretic tissue clearing with one commercial Clarity Chamber, the set is 37 degree, and 1.5mA. After 2 days, I checked the brain sample, and found the size of brain enlarged almost twice and color become yellow, kind of semi-transparents. Anyone know what caused this? specially yellow color? Thanks!