Chapter 26 High-Resolution Microscopic Methods for the Analysis of Cellular Movements in Drosophila Embryos

This chapter outlines the various methods used for the observation and documentation of living fly embryos. It primarily focuses on high-resolution methods used for observing and recording images of living embryos that take advantage of a number of advancements in video microscopy and digital image processing. New advances in electronic image detection greatly facilitate image acquisition and manipulation so that high-quality electronic images now compete with the best photographic film images. Given appropriate instrumentation, an image can be easily acquired, manipulated, and transferred to hard copy in a fraction of the time required to produce comparable output by photographic methods. High-fidelity electronic imaging implies that resolution, ideally diffraction limited as output from the microscope, stays optimal throughout image recording, digital image processing, and image outputting to hard copy. A wide variety of algorithms designed to enhance contrast are available for manipulation of a digitally recorded image. This enhanced contrast can bring out detail in images crucial to evaluate relevant elements of structure in the developing embryo. Such algorithms compare individual pixels to those that surround them.