minutes to hours. This not only calls for a suitable environment with controlled
temperature, humidity, and a stably buffered culture medium [7], but it also
requires economizing light exposure, since living cells are subject to photo-
damage [8]. In fluorescence microscopy, excessive illumination bleaches fluor-
ophores, and this limits their emission time span and generates free radicals that
are toxic for living cells.
Two very important factors determine whether automated methods can be
applied successfully, and they strongly affect accuracy. They are signal contrast
(the intensity difference between objects and background) and noise, which, in
light microscopy, is signal dependent. These two factors are usually combined
into a single measure, the ...