Control material and methods for cell analyzers

A method of verifying the operation of a cell analyzer having an automated microscope and image processing software for counting and analyzing cells and platelets in blood and which utilizes a test cartridge having a diluent/and or stain, the method comprising:

• a) introducing into the test cartridge a mixture of 1) a plurality of a first type of micro-beads in a known amount of solution having a first known characteristic and a concentration that simulates a concentration of a first type of cells in blood and 2) a plurality of a second type of micro-beads in a known amount of solution having a second known characteristic and concentration that simulates a concentration of a second type of cells in blood;
• b) interfacing the test cartridge with the cell analyzer;
• c) separating a known amount of the mixture of micro-beads from the remaining amount of the mixture of micro-beads in the test cartridge;
• d) mixing the known amount of the mixture of micro-beads in the test cartridge with an amount of diluent and/or stain that is sufficient to form a substantially uniform mixture of micro-beads and diluent and/or stain, wherein the micro-beads are suspended therein;
• e) transferring the entire mixture into the imaging chamber that is defined in the body of the test cartridge;
• f) allowing the particles in the mixture to settle to a bottom of the imaging chamber;
• g) capturing one or more digital images of the settled particles in the imaging chamber that are selected to be statistically representative of the number and distribution of the first and second types of micro-beads;
• h) counting all of at least one type of micro-beads in the images using imaging processing software;
• i) obtaining a number of micro beads per unit volume of at least the one type of micro-beads in the mixture;
• and
• j) comparing the number of micro-beads per unit volume of the one type of beads in the imaging chamber with the concentration of the one type of beads in solution.