1. A method for performing a staining procedure for a biological sample, the method comprising: recording a first image of the sample; applying a staining agent to the sample so as to prepare a stained sample comprising a plurality of stained entities and/or a plurality of superficially stained entities; recording a second image of the stained sample; generating a first difference image by comparing the second image to the first image so as to determine a location of at least one of the stained entities on the stained sample, if present; applying a decolorizing agent to the stained sample so as to prepare a partially decolorized sample wherein at least a portion of the staining reagent is removed from the superficially stained entities, if present; recording a third image of the partially decolorized sample; generating a second difference image by comparing the third image to the second image so as to determine a location of at least one of the superficially stained entities on the stained sample, if present; and analyzing the second difference image to determine an exposure time during which the decolorizing agent could be applied to the partially decolorized sample to substantially decolorize the superficially stained entities, if present, without substantially decolorizing the stained entities, if present.