thick sections ( 0.5 -- 2 mu ) of biopsies from human nervous system tumors ( schwannoma , ependymoma , medulloblastoma ) , fixed in aldehydes followed by osmium , and stained with uranyl acetate and lead , have been studied at 2.5 mv , and compared to thin sections of the same material observed by ordinary low voltage electron microscopy .
C0027766
of
C0025149
medulloblastoma