| abstract |
A dye composition for differential analysis of white blood cells comprising a hypotonic aqueous solution of a metachromatic fluorochrome dye, e.g., acridine orange. The solution has a pH factor within normal physiological ranges for human blood. The white cell analysis is made by straining the cells with the fluorescent dye by suspending a sample of fresh blood in the dye solution, subjecting the suspension before dye uptake equilibrium is reached to radiation from a light source (e.g., radiation from a blue laser) having a wave length within the range of absorption of the dye, distinguishing the white cells from other blood particles by detecting fluorescenses (e.g., green fluorescences) emitted from the white cells in response to the radiation, and further distinguishing the various types of white cells by measuring the magnitudes of their respective fluorescence emissions (e.g., red and green fluorescences). Differences in the rates of uptake of fluorochrome dye of the various kinds of white cells are accentuated by altering the aqueous dye solution so that it becomes hypotonic. |