Methods for the measurement of multiple parameters of erythroid regulation within individual mice.

Hematocrit, hemoglobin p50, percent reticulocytes, rate of erythropoiesis using 59Fe, and blood volume were determined in individual mice using a single blood sample. Furthermore, sufficient blood remained to provide a serum pool from no more than five mice for an erythropoietin assay. These multiple procedures did not interfere with one another, and the various measurements did not need to be made immediately. Freshly prepared 51Cr-labeled erythrocytes were, however, required for blood volume determinants.