Apafix fixation as a new option for the study of animal and human tissues

Fixation is a physico-chemical phenomenon and reactions involving gradual diffusion of fixative into the tissues. It is an essential step in the evaluation and study of biopsy tissue specimens. It aids in the preservation of the tissue's cellular architecture and composition during processing. Fixation also maintains the spatial connection of proteins, carbohydrates, and other bioactive moieties to the cell, allowing them to be examined. For more than a century, the fixative of choice in routine histopathology has been a 10% solution of formalin (4% formaldehyde) diluted in water or in a buffered solution. Formalin maintains chemical activity and cellular antigenicity in tissues by forming covalent bonds between biological macromolecules. As a result, formalin-fixed paraffin-embedded (FFPE) tissues are now the most widely used fixatives in the world. However, formalin is not always the 'gold standard' fixative when other downstream biochemical and molecular analyses are considered. The benefits of formalin as a histological preservation are outweighed by a variety of drawbacks, the most prominent of which are diminished immunohistochemical reactivity and rapid nucleic acid breakdown. Consequently, Apacor has discovered a new fixative named apafix, in order to overcome the issues associated with formalin. In the current research, the effects of apafix will be investigated in animal tissue morphology using histological analysis.

Apafix was seen to preserve the colour of animal tissues well after fixation, as well as the structures of certain animal tissues well (e.g. ileum) and minimised shrinkage, unlike formalin preserved tissues (e.g. brain).
Under the microscope, apafix has shown to express a greater scope of detail of the tissues and commonly displays cells individually, enabling cells to be well defined (e.g. ileum).
Apafix preserved tissues have shown to stain with H+E significantly better compared to formalin preserved tissues.
Overall, it seems apafix results were as good as formalin and even greater within some tissues.