osmic acid fixative

os·mic ac·id fix·a·tive

a fixative used alone in buffer or as a postfixative after a glutaraldehyde fixative in electron microscopy; an excellent membrane fixative but a poor preservative of chromatin.
References in periodicals archive ?
The peptic ulcer tissue was fixed in 4% paraformaldehyde and 1% osmic acid fixatives for electron microscopy.