osmium tetroxide uranyl acetate ref name ross pawlina main action aldehyde fixatives cross link amino groups proteins formation methylene bridges ch sub sub case formaldehyde c sub sub h sub sub cross links case glutaraldehyde process preserving structural integrity cells tissue damage biological functionality proteins particularly enzymes formalin fixation leads degradation mrna mirna dna well denaturation modification proteins tissues however extraction analysis nucleic acids proteins formalin fixed paraffin embedded tissues
Natural science Biology Histology