Principle: Through the synergistic action of paraformaldehyde (fast penetration) and glutaraldehyde (deep cross-linking): paraformaldehyde first penetrates the cell to form a primary cross-linking network, and glutaraldehyde then forms a stable five-membered ring structure with the free amino group of proteins through the bis-formaldehyde group (-NH2) to ultimately achieve: ① complete retention of the lipid bilayer of the cell membrane; ② precise fixation of the spatial localization of organelles; and ③ maximal preservation of the epitopes of antigens. (Retention rate＞90%).

Main components: paraformaldehyde, glutaraldehyde