Preparation of Drosophila eye specimens for scanning electron microscopy

Scanning electron microscopy (SEM) allows for high-magnification analysis of the external structures of the Drosophila eye. In this article, three methods are provided: one for eyes that are to be critical-point-dried (CPD) and two alternatives if a critical point drier is not available. The major difference between the first method and the other two is a preliminary fixation step. Drosophila eyes have a tendency to collapse when CPD, so fixing the animals before critical point drying improves the yield of good specimens.