Immunologic similarities of thrombopoietin from different sources

Thrombopoietin (TSF) has been detected in kidney cell culture media and human urine fractions by both a bioassay and an immunoassay using antisera raised against TSF-rich kidney cell culture medium and human urinary thrombopoietin. Both antisera cross-reacted with the 2 sources of TSF and gave essentially the same results in the HAI assay, a finding that suggests similarities in immunologic determinants of these 2 thrombopoietin preparations.