A method for enumerating platelets within a blood sample is provided. The method includes the steps of: 1) depositing the sample into an analysis chamber adapted to quiescently hold the sample for analysis, the chamber defined by a first panel and a second panel, both of which panels are transparent; 2) admixing a colorant with the sample, which colorant is operative to cause the platelets to fluoresce upon exposure to one or more predetermined first wavelengths of light; 3) illuminating at least a portion of the sample containing the platelets at the first wavelengths; 4) imaging the sample, including producing image signals indicative of fluorescent emissions from the platelets, which fluorescent emissions have an intensity; 5) identifying the platelets by their fluorescent emissions, using the image signals; 6) determining an average fluorescent emission intensity value for the individual platelets identified within the sample; 7) identifying clumps of platelets within the sample using one or more of their fluorescent emissions, area, shape, and granularity; and 8) enumerating platelets within each platelet clump using the average fluorescent emission intensity value determined for the individual platelets within the sample.