Double Embedding Broad Thin Leaves in Paraffin

Abstract

Paraffin pellets were melted in 24 × 24 × 5 mm stainless steel base molds. Specimens of leaves, 18 × 18 mm, were fixed, dehydrated and infiltrated with paraffin. Two specimens were transferred into molten paraffin on their laminar surfaces in a base mold and moved quickly onto a cold surface to cast them in a shallow block of paraffin. Each block was then scored with a razor blade, broken into two primary blocks, and trimmed to 20 × 9 mm with 5 mm flat edges. Each primary block was immersed upright on its long edge in a 22 × 22 × 20 mm Peel-A-Way® embedding mold containing molten paraffin. The leaf edge was held centrally in the mold while moving the double embedment onto a cold surface. In this secondary block, the leaf specimen stood perpendicular to the sectioning surface in perfect orientation for transverse ribbon sectioning. The two phases of paraffin bonded well.

Key Words:

• double embedding
• paraffin sectioning
• leaf specimens