Fixation of Drosophila embryos.

INTRODUCTIONA number of techniques are available for fixation of Drosophila embryos, each with their own advantages and limitations. The technique appropriate for a specific study will depend on a number of variables, including the preservation qualities of the cellular components to be examined, the position of the components within the embryos, and the probe used. Formaldehyde-based techniques are useful for preserving deep and/or cytoskeletal elements. Fixation with methanol or boiling is harsher, but both result in nearly total devitellinization of the embryos. Fixation without methanol requires devitellinization of the embryos by hand. While the most tedious, this latter method often produces the highest-quality results. It may be necessary to try all of these techniques to determine which one is the most appropriate for each new antibody or reagent.