I did mitoisolation in zebrafish in the MB buffer of following composition: Filter-sterilize and store at 4°C for a maximum of 1 month. Consists of 210 mM mannitol, 70 mM sucrose, 1 mM EDTA, 10 mM HEPES (pH 7.5) containing protease inhibitors. I got a very pale whitish pellet which should be yellowish brown. Any ideas how to interpret the pellet colour.