Brand augments naturally occurring fluorescence in proteins with special probe molecules that are placed with the proteins under study, and can help signal changes in the shape of a protein. If you looked at a protein when you turned the laser off, the fluorescence would seem to disappear immediately. But it isn't immediate. As proteins shed energy imparted by the laser, their physical and chemical properties, as well as their immediate surroundings, affect the way this energy is given off as light. Individual molecules can also affect fluorescence by transferring energy to each other, a process dependent on the distance between the molecules.
Brand also can use fluorescence to measure the tumbling of proteins on short time scales.
On their own and with research partners in biology, biophysics, chemistry, medicine and engineering, Brand and the members of his lab have applied fluorescent spectroscopy to many different problems. In some MS patients, myelin becomes detached from nerve cells. Russo and other researchers in Brand's lab built an artificial membrane to simulate a nerve cell membrane, and used fluorescent spectroscopy to study how the membrane interacted with myelin basic protein. Late last year, Vikas Nanda defended his doctoral thesis on work completed in the Brand lab. Nanda set out to use fluorescence to study homeodomains, regions in proteins that bind to DNA to control gene activity.