Camwood (Baphia nitida) Extract as a Histological Stain for Interglobular Dentine, Striated Muscle, and Counterstaining

Abstract

The shavings of the dried heartwood of the tree Baphia nitida are ground to a fine powder, and 6 gm of the powder are extracted in 100 ml absolute ethanol at 27–30 for 6–24 hr. The extract is filtered with Whatman No. 1 paper and stored in a screw-capped bottle. For staining the interglobular dentine of nondecalcified sections of formlin-fixed teeth, sawed cross sections 20–30 μ thick were dehydrated in ethanol and stained in the undiluted extract for 6–12 hr at room temperature. The interglobular dentine was stained a bright golden brown on a pale brown background. For staining striated muscle, the extract was diluted 1:1 with distilled water and filtered. After mordanting formalin-fixed paraffin sections with 0.25% KMnO₄ for 5 min, and bleaching with 5% oxalic acid for 10 min, they were washed in water and stained for 2–24 hr at room temperature. The striations were stained light to deep golden brown. For use as a counterstain, a 1:6 dilution of the original extract was required. When applied after haematoxylin for 15–30 min, it stained tissue components in varying shades of golden brown with distribution comparable to that produced by 1% eosin.