Morphology, staining, and RNA quality after fixation in different fixatives.

Morphological evaluation of haematoxylin stained tissue, compatibility with NBT BCIP, Kiel and ORO staining protocols and RNA quality of frozen tissues after 10 minutes fixation in different fixatives. The morphology was rated from haematoxylin stained tissues in a scale from + to +++, where + is poor morphology, ++ is intermediate and +++ is very good morphology. ORO, Kiel and NBT BCIP stainings were evaluated as absent (−), weak (+), medium (++) or strong (+++). The histological evaluations were performed by 2 independent observers. RNA quality was assessed using RIN values, average (95% confidence intervals).