Abstract: The present invention relates to a process for determining the influence of a condition on a biological sample comprising a step consisting in establishing the kinetic profile of the fluorescence emitted, during the excitation at a suitable excitation wavelength, of a fluorescent compound bound to said biological sample, said sample having been, prior to said excitation, subjected to said condition and said process not necessitating the utilization of a fluorescence donor component and of a different fluorescence acceptor component. The present invention also relates to the various applications of such a process.