A study of section wrinkling on single-hole coated grids using TEM and SEM.

To prevent section wrinkles usually encountered with the use of coated single-hole grids, a simple method was developed. Formvar film resting on a platform with holes (3.5 mm diameter) was heated with a slide warmer (60-65 degrees C). The bottom of a glass petri dish was inverted over the platform to keep the ambient air at the desired temperature. Sections were picked up from the boat of the diamond knife with a single-hole grid and deposited at the orifice of the platform and allowed to dry. The grids were then carefully pushed through the orifice of the platform with the blunt head of a nail (3 mm diameter).