GAF vs. Formalin: A turning point in forensic tissue preservation

Abstract

Formalin's widespread use in tissue fixation for forensic and diagnostic pathology is increasingly challenged by its known carcinogenicity and detrimental effects on biomolecular integrity. This technical note evaluates Glyoxal Acid-Free (GAF) fixative as a superior, non-toxic alternative. We highlight formalin's limitations in terms of occupational hazards and compromised molecular analysis (e.g., DNA degradation for NGS and epitope masking for IHC). Subsequently, we present the advantages of GAF, including excellent morphological preservation, enhanced immunohistochemical performance, and "in press" results about superior preservation of nucleic acids, crucial for advanced molecular techniques. Furthermore, GAF demonstrates remarkable long-term tissue stabilization, supporting its utility for both current and retrospective forensic investigations.

Keywords: Carcinogenicity; DNA integrity; Forensic pathology; Formalin; Glyoxal; Immunohistochemistry; Next-generation sequencing; Tissue fixation.