Pathology laboratory in Formalin free system

Formalin fixation in surgical pathology is a major limiting factor to medical research and development of molecular techniques for target based medicine. Search for alternate solution of formalin fixation in the histopathology laboratory to preserve the macromolecules has led to development of various substitutes with substantial technical advantages. Though DNA and RNA could be extracted from formalin fixed archival material, the limitations have come to forefront, necessitating development of new tissue fixatives preserving the chemical nature of the proteins and antigen epitopes, so that diagnostic and biochemical characterisation is enhanced. The alcoholic fixatives preserve the tissue by causing precipitation of proteins and devoid of cross linking unlike with formalin. The application of newer commercial fixatives like Fine-Fix, universal molecular fixative (UMFIX), RCL2 have been reported to enhance the integrity of macromolecules for molecular analysis along with accurate morphological details for tissue diagnosis. Modified Methacarn fixation provides an ideal combination of maximum staining and morphological preservation of most of the antigens and is cost effective. Zinc based fixatives can avoid formalin and be prepared in the laboratory at low cost. The patented vacuum device facilitates transporting large tissues in a formalin free environment and preserves tissue integrity for diagnosis and tissue banking. Knowledge of the basic chemistry of tissue fixatives, the biochemical changes that take place in the biological materials, by cryopreservation and chemical fixation is essential while undertaking the genomic and proteomic studies on fresh and archival tissue banking.