A new method using acid to clean and a technique for preparation of eggs of biting midges (Diptera: Ceratopogonidae) for Scanning Electron Microscope

Abstract

A new procedure for clearing eggs belonging to genera of Ceratopogonidae is described. In the new procedure eggs in different states, with different ultra structures of the exochorion, were immersed in 10% glycolic acid (CH2OH-COOH) and 20 % mandellic acid (C6H5.CHOH.COOH) for 1–4 minutes. Eggs, prepared by both acids and subsequently neutralized by distilled water, were placed in a saturated solution of phenol, and then passed through a battery of alcohol solutions. Finally, critical point was performed and gold metallized. After preparation the eggs of this group retained their natural form under vacuum long enough to yield good microphotographs of the outer layer of the chorion.