Multi-Pulse Fluorescence

Multi-Pulse Fluorescence (MPF) is a new CFS core project, currently under development.

The basic idea of MPF is to perturb the sample with one light pulse and to start the time-resolved measurement at a delay time t with a second excitation pulse. The time-resolved data will be correlated with time-dependent structural changes in the protein following the perturbation pulse. This approach will be applied to proteins which undergo conformational changes in response to light, including hempglobin, rhodopsin and phytochromes. Both steady state and time-resolved measurements will be performed.

Figure : Experimental arrangement for two-pulse fluorescence measurements. L are lenses, P are polarizers, D are diaphragms, R are polarization rotators, and F are optical filters. Long delay line DL1 is placed in the UV and a fine delay line DL2 in the visible beam, DF is a coated optical plate (dichroic filter) and PD is a reference photodiode, used in time-resolved measurements.