This 3.7% Paraformaldehyde solution is a neutral fixative widely used in immunohistochemistry and immunocytochemistry applications. It cross-links proteins and nucleic acids to preserve cellular and tissue architecture, effectively immobilizing structural components. Typically stabilized in phosphate buffer, it ensures specimen integrity during processing and staining. Its gentle fixation properties allow for clear visualization of detailed cellular structures under the microscope, maintaining morphology without excessive hardening or distortion.