Paraformaldehyde-Glutaraldehyde Mixed Fixative (2%/2.5%) is a widely employed mixed fixative in electron microscopy, consisting of 2% paraformaldehyde and 2.5% glutaraldehyde, buffered with phosphate buffer to maintain a pH of approximately 7.4. This fixative is particularly suitable for the preservation of cellular ultrastructure in electron microscopic observation, as it rapidly crosslinks proteins at the molecular level, effectively prevents autolysis, and maximally preserves the native state of organelles and subcellular structures. Compared with glutaraldehyde used alone, the inclusion of paraformaldehyde enhances membrane penetration while better preserving antigenicity. It should be noted that this fixative is not suitable for fixing nucleic acids or polysaccharides, as its fixation mechanism is primarily directed at proteins and is less effective for other biological macromolecules.
危险品化学品经营许可证（带存储）