Preparation of Leaf Epidermis for Topographic Study

Abstract

Epidermal strips of leaves of the Gramineae can be prepared using the following technique: The mature leaf is dipped in boiling water to kill the cells, and decolorized in boiling 70% alcohol. It is cleared and softened in 88% lactic acid. Epidermal, mesophyll and vascular tissue is removed from a selected constant area of the leaf leaving an epidermal strip 1-3 cm in length. This is inverted on a slide, stained in lactopheno-cotton blue, and destained in 88% lactic acid. Transverse and longitudinal sections of the strip are obtained at this stage. The epidermal strip is finally mounted on a slide in 88% lactic acid. The preparation is photographed with a 35 mm camera using transmitted light, and a yellow filter in the microscope lamp. Photomicrographs of known enlargement are then prepared from which accurate measurements can be recorded. The technique is applicable to both fresh and herbarium material.