Eco-friendly natural fixatives – a substitute for formalin?

Fixation is the critical step in the preparation of tissues for routine histopathology in which Formalin is the universal fixative. The fundamental advantage stems from its continuous and almost universal use for over 100 years and all the accumulated scientific knowledge on it. Also, formalin is readily available, economical, fairly convenient to store, allows long-term storage, preserves lipids well, and has been accepted the perfect fixative, with no clear “all purpose” alternative found to date. However, formalin has well known disadvantages like high toxicity and classified as a human carcinogen. It binds severely to DNA, RNA and proteins, which makes them difficult or impossible to extract in a useful form for molecular tests. However we explored more economical, eco-friendly and readily available substances like sugar, honey and jaggery which have shown to have the potential to preserve compounds without any harmful effects. They are advantageous in that they are non- hazardous, compatible with routine processing, staining, do not require additional equipments and are easily available at any place. Hence the present study is undertaken with an aim to compare the tissue fixation abilities of honey, sugar syrup and jaggery syrup with that of formalin followed by H & E staining in order to determine the best fixative.