title: Softening of plant specimens (Equisetaceae) to improve the preparation of paraffin sections.
abstract: A method is presented for softening the hard tissues of stem and strobile of Equisetum giganteum allowing the preparation of representative histological slides suitable for teaching and research. Segments of aerial portions of the Equisetum giganteum shoot system were fixed with formaldehyde:ethanol:acetic acid (5:10:5) for 24 hr at room temperature, washed in distilled water and immersed in a mixture of 5% hydrofluoric acid and 0.5% sulfuric acid for 1 hr at room temperature. Hydrofluoric acid has a higher affinity for silica components, and the sulfuric acid acts as a catalyst favoring the separation of calcium silcates. This simple, inexpensive and rapid method allows paraffin sections to be prepared while preserving the topographic microanatomy by decreasing technical artifacts produced by conventional softeners, and preserving PAS-positive polysaccharides.
authors.affiliation: Laboratory of Cell Biology, Faculty of Sciences, University of Córdoba, Argentina.
authors.forename: V H
authors.initials: VH
authors.lastname: Tomasi
authors.forename: R A
authors.initials: RA
authors.lastname: Rovasio
mesh_terms: D016612:Paraffin Embedding / Q000379:methods*; D010944:Plants / Q000648:ultrastructure*; D013048:Specimen Handling; D013501:Surface-Active Agents
chemical_list: D013501:Surface-Active Agents