“With the emergence of specialized microscopy units at most universities and research centers, the use of these techniques is well within reach for a broad research community.”

Advances in molecular biology, organic chemistry, and materials science have recently created several new classes of fluorescent probes for imaging in cell biology. The possibilities are endless.

The probes can be used to study proteins on many levels: in live or fixed specimens; in vitro or in vivo; to study localization, activity, or modify function; and to be seen by light and electron microcopy.

With the emergence of specialized microscopy units at most universities and research centers, the use of these techniques is well within reach for a broad research community. However, the fluorescent toolbox has become very complex and each tool has specific requirements and pros and cons for different applications. Our review gives a short summary of these current tools, which is currently not yet available in text books.

The paper describes recent methods and applications for cell biologists to study proteins at the microscopic level. The authors have contributed to development of these probes and optimized and applied several of these techniques. Micrographs of the authors’ work illustrate the potential of the techniques.

To understand the molecular mechanisms of cellular regulation, we need to study these molecules in action in live cells. Such observations have become far more practical in recent years because of the new fluorescent and electron microscopic methods we describe.

We have a long-standing interest in breaking existing barriers in biological research by developing new methodology, techniques, and probes. Such pioneering always encounters many problems both in the intrinsic technology and its subsequent biological application.