A cross-sectional study to correlate nuclear fixative properties of formal saline and clarke’s fluid for histomorphology evaluation of human tissues

Abstract Background: Formal saline is an extensively used cheapest and easily available tissue fixative. However, formalin has been proven to have carcinogenic effects. Clarke’s fluid is an alternative to formal saline and is effective in maintaining the morphological and cellular architecture. Objectives: The objective of the study was to compare the nuclear fixative properties of Clarke’s fluid and formal saline. Materials and Methods: The fresh human tissues of thin skin, large-sized arteries, lymph nodes, spleen, and ileum were obtained from the fresh cadaver. The tissues were fixed in two different fixatives namely 10% formalin and Clarke’s fluid. Then, the tissues were histologically processed. The hematoxylin and eosin-stained serial sections of tissues were graded based on the ease of microtomy, cytoplasmic, and nuclear staining scores. Results: The nuclear properties of all the tissues immersed in Clarke’s fluid showed a median score of 3 and Grade 2 for formal saline; cytoplasmic properties for spleen and skin were median scores of Grade 3 for Clarke’s fluid. The artery was graded 3 for both the fixatives. The Kruskal–Wallis test when applied to nuclear properties, cytoplasmic adequacy, and tissue shrinkage for tissues stained with Clarke’s fluid was statistically significant ( P < 0.01). This inferred that Clarke’s fluid is a better nuclear fixative than formal saline. Conclusion: The imminent risks associated with formal saline paved us to explore substitute fixatives, which could provide better results and safety for laboratory workers. Clarke’s fluid is an excellent substitute for formal saline as a nuclear fixative.