Patent ID: 8744164

Claim:
A method of automatically identifying the number of cells present in a sample, comprising the steps of: providing an optically transparent supporting surface, said optically transparent supporting surface situated for observation in an optical microscope having a sensor sensitive to optical illumination, said sensor having an output terminal configured to provide as output a signal representative of a field of view monitored by said sensor; providing a sample comprising at least one cell situated on said optically transparent supporting surface; deliberately operating said optical microscope in bright field mode with optical illumination so as to focus at one or more different focal planes situated along a direction normal to said optically transparent supporting surface, so that said at least one cell is within said field of view of said sensor; observing with said sensor an image selected from the group of images consisting of an image having one or more bright spots and an image having one or more dark spots, said image having one or more bright spots and said image having one or more dark spots generated even when said sample is free of a label, said image corresponding to an out-of-focus condition; providing from said output terminal of said sensor an output signal representative of said image; processing said output signal representative of said image to compute a number of bright spots or a number of dark spots; and reporting said number of bright spots or said number of dark spots as the number of cells present in said sample.