Live Confocal Analysis with Fluorescently Labeled Proteins

The development of laser scanning confocal microscopy provides a powerful means to observe structures and components within the cell. Equally important advances have also occurred in the development of reagents and techniques for generating functional fluorescently tagged proteins. When these labeled proteins are used in conjunction with confocal and other advanced fluorescence microscopes, the dynamics of a given protein within the living cell can be readily analyzed in real time. Live analysis provides an appreciation of the cellular and developmental dynamics that is virtually impossible to obtain through observation of fixed samples. In addition, tracking down the primary defect and determining causal relationships in mutant and drug-mediated phenotypes often can be accomplished only through live fluorescence analysis. Finally, live analysis has been used to confirm the existence of structures in the embryo that were previously contested as possible fixation artifacts (1 ).