A method for analyzing spatial and temporal information of samples using optical microscopy includes choosing a field of view in a sample; scanning the sample by applying an electrical signal having a first frequency to an electrically tunable liquid lens in the detection path, performing a sequential acquisition, at a first acquisition frequency higher than the first frequency of the electrical signal, of a stack of images placed on different in-focus planes; processing the stack of images to identify the position of one or more regions of interest; scanning the sample by applying the electrical signal having a second frequency to the tunable lens, performing a sequential acquisition, at a second acquisition frequency lower than the second frequency of the electrical signal, of a temporal series of images with extended depth of field; and calculating the mean intensity of each region of interest for each image of the temporal series.