Erythropoietin assay by hemagglutination-inhibition.

The immunochemical assay (HAI) for erythropoietin is accurate enough to detect small quantities and sensitive enough to demonstrate consistently and quantitatively the presence of erythropoietin in serum and urine. It will be the purpose of this report to describe in detail the procedure for the assay, the usefulness and value of erythropoietin testing in the clinical laboratory. The relationship of erythropoietin levels in serum and urine in the classification of diseases of the red blood cells are discussed. There is presently no other method available for the measurement of erythropoietin that permits the detection of extremely small differences, sensitive enough to demonstrate consistently and quantitatively the presence of small amounts of erythropoietin.