Cell biology is the discipline that studies cells to answer scientific questions. All organisms are composed of one or more cells and all vital functions of an organism occur within cells. Cells contain the hereditary information necessary for regulating cell functions. Cells possess DNA, the hereditary material of genes, and RNA, containing the information necessary to build various proteins such as enzymes, the cell's primary machinery. There are also other kinds of biomolecules in cells, e.g. lipids, proteins, macromolecules, and more.
Inside cells specific interactions between biomolecules are involved in almost any physiological process. Sensing extracellular signals is a matter of receptor to adapter interactions and an intricate network of structural protein interactions maintains the shape of the cell. Finding interactions between proteins involved in common cellular functions is a way to get a broader view of how they work co-operatively in a cell. One way to observe biomolecular interactions is by doing FRET measurements. In this article some examples of different interactions are given, with the link to the paper in question.
Confocal imaging on a widefield fluorescence microscope can now be done in combination with frequency domain FLIM. The increased spatial resolution in the z-direction results in lifetime images with enhanced contrast as the detection of out-of-focus emission is reduced significantly. This allows you to see differences in fluorescence lifetime e.g. between the cell membrane and the cytoplasm. Read more about the technology of confocal imaging or view the LIFA confocal product with a photo of the set-up.