A method and apparatus for identifying reticulocytes within a blood sample is provided. The method includes the steps of: a) depositing the sample into an analysis chamber adapted to quiescently hold the sample for analysis, and the chamber has a known or determinable height extending between the interior surfaces of panels, which height is such that at least one red blood cell, or an aggregate of red blood cells, within the sample contacts both of the interior surfaces; b) admixing a supravital dye with the sample, which dye is operable to cause reticulin to fluoresce when excited by light of one or more predetermined wavelengths; c) imaging the sample using light that includes the one or more predetermined wavelengths that cause reticulin to fluoresce; d) imaging the sample using light that is absorbed by hemoglobin to produce values of optical density on a per image unit basis; and e) identifying reticulocytes within the sample using the image of the sample created with light that causes the dyed reticulin to fluoresce, and using the per image unit optical density values.