A Method for Epicuticular Wax and Contaminant Removal from Herbarium Specimens for Scanning Electron Microscopy

Abstract

We describe a method for cleaning leaf epicuticular wax and contaminants from herbarium specimens in preparation for scanning electron microscopy. Specimens are rinsed in chloroform, heated at 50°C for 8 hrs, ultrasonicated in 70% ethanol, and subjected to critical-point drying. This method helps preserve and reveal the surface details of specimens that are heavily covered with epicuticular wax and contaminants, making many morphologically and functionally important details readily visible. We tested our method by using it to clean herbarium specimens and comparing the results with those obtained using three other chemicals: acetone, xylene, and 1:1 acetone:xylene, confirming that chloroform treatment was the most effective.