ABSTRACT
A simple in vivo bioassay suitable testing of quality control of recombinant human erythropoietin (rHu-EPO) analogues was developed. Mice made polycythemic by intraperitoneal injection of 1.2 ml of a 80 per cent suspension of heterologous (rat) red cells were used as assay animals and splenic 59 Fe uptke as expression of the response to rHu-EPO. The assay took three days and the following schedule is propose: 1)intraperitoneal injection of 1.2 ml of washed packed red cells obtained from donor rats, 2) subcutaneous injection of test material 4-5 h after transfusion, 3) intravenous administration of 59 Fe tracer 48 h later, and 4) determination of splenic isotope uptake 6 h after injection. This method for the in vivo biossay of rHu-EPO analogues is an economical and reliable alternative to the existing bioassays of the hormone