Patent ID: 7176031

Claim:
A flow cytometry reference control composition for measurement of nucleated blood cells comprising a first set of synthetic spherical particles having a mean particle diameter in a range from about 6.2 μm to about 6.8 μm and a refractive index from about 1.58 to about 1.62, enabling simulation of optical properties of partially lysed nucleated red blood cells having a size ranging from 3.9 μm to about 4.7 μm; a second set of said synthetic spherical particles having a mean particle diameter in a range from about 7 μm to about 12 μm, a refractive index from about 1.58 to about 1.62 and optical properties simulating optical properties of white blood cells as measured by optical measurements; a blood cell component; and an aqueous suspension medium; wherein a ratio of said first set of synthetic spherical particles to said second set of synthetic spherical particles is within a range up to about 0.5 to simulate said nucleated red blood cells in a concentration range up to 50 per 100 said white blood cells.