Differential Staining of Tannin in Sections of Epoxy-Embedded Plant Cells

Abstract

A staining procedure is described for the light microscopic localization of ergastic tannins in epoxy sections of plant cells embedded for study by transmission electron microscopy. Callus and cell suspensions of Pseudotsuga menziesii and Pinus taeda fixed in glutaraldehyde:acrolein and then OsO4, followed by epoxy embedding, were sectioned 0.5 mum thick, stained on a glass slide with ethanolic Sudan black B at 60 C as described by Bronner, and then mounted in Karo syrup. Tannin deposits stained brownish-orange and were easily distinguished from lipid bodies of similar size, which stained dark blue to black, and from starch grains, which were unstained. The significance of this differential polychromasia was confirmed by transmission electron microscopy. This staining procedure should prove valuable in the cytoplasmic evaluation of the plant cell ergastics (especially tannins) via light microscopy whether or not electroc microscopic examination is intended.

Occurrence of tannins in leaves of beech trees (Fagus sylvatica) along an ecological gradient, detected by histochemical and ultrastructural analyses

“…These sections were stained with uranyl acetate and Reynold's lead citrate, and then observed with a Philips2 EM-300 microscope. Electron microscopy observations show tannins as electronopaque structures, due to the osmiophilic properties of these substances (Parham & Kaustinen, 1976 ;Soikkeli, 1978 ;Rao, 1988).…”

The Synthesis and Storage Sites of Phenolic Compounds in the Root and Rhizome of <i>Echinacea purpurea</i>

“…Because the phenolic compounds would be strongly stained by osmium tetroxide [19], and the product could be easily recognized in a form of aggregates [20], the distribution of the electron opague product from the osmium tetroxide stained phenolic acids in the cells was further examined by electron microscopy. Under electron microscope, there was light cytoplasm and a typical centric big vacuole in the mature of cortex parenchyma cell of the two-year old rhizome.…”

Variation in stem morphology and movement of amyloplasts in white spruce grown in the weightless environment of the International Space Station

“…In the present study, these compounds reacted with toluidine blue O and osmium tetroxide. As phenols are known to be stained by toluidine blue O (Harling and Taylor, 1985;Baayen et al, 1996;Rioux et al, 1998) and frequently react with osmium tetroxide (Parham and Kaustinen, 1976;Franceschi et al, 1998;Li et al, 2012), we have good reason to believe that they were indeed of a phenolic nature in the present study. It was frequent to see artefacts such as holes within such phenol bodies (Fig.…”