Erythropoietin (or EPO) is a glycoprotein hormone that is a growth factor for erythrocyte (red blood cell) precursors in the bone marrow. It directly increases the number of red blood cells in the blood. EPO has been extensively used as a performance enhancing drug, particularly in cycling and long-distance running, because higher amounts of red blood cells can increase the oxygen carrying capacity of the blood and therefore improve endurance.
The activity of an unknown erythropoietin preparation is determined by comparison with a reference preparation. The assay is based on the flow cytometric measurement of stimulation of reticulocyte production in normocythaemic mice.
The final estimation of potency is based on the parallel-line model and may be carried out with our bioassay software package PLA 3.0. For estimating the percentage of reticulocytes directly from the flow cytometric raw data we have already developed an extended data acquisition module.