Staining Property of Alcoholic and Aqueous Hibiscus sabdariffa Extract in Demonstration of Selected Bacteria in Tissue Sections of Wistar Rats

Abstract

Introduction: Dye is used for the artificial colouration of a substance to facilitate its examination by the use of the coloured organic molecule, a process called staining. Over the past many years, it has been observed that synthetic dyes have many disadvantages associated with them like toxicity and allergenicity. This study aimed to determine the staining effect of Hibiscus sabdariffa extracts of various concentration, various pH and duration in bacteria staining compared with Gram’s staining. Methods: Standard Gram stains as control and both Hibiscus sabdariffa extracts (alcohol and boiled water) were used to stain inflammatory appendix tissue and lung tissue inoculated with bacteria using various concentration (5% and 10%), at various duration (30 seconds and 1 hour) and with change of pH, achieved by treating the extracts with ammonium hydroxide and glacial acetic acid. Each was used as a counterstain in bacterial stain (to replace Safranin/Neutral red) Safranin/Neutral red. Results: All extracts after treatment were acidic but the change of pH was indirectly proportional to the staining ability of the extracts. The Hibiscus solutions gave the background, a brown colouration. And inflammatory cells were demonstrated better than the bacteria with aqueous Hibiscus solution strongly when compared with the alcoholic Hibiscus solution. Conclusion: The results obtained indicate that Hibiscus solution has the potential for use in diagnostic bacteriology in formalin-fixed paraffin-embedded tissue section.