Partial Purification of a Thrombocytopoiesis Stimulating Factor Present in the Serum of Thrombocytopenic Rats

Abstract
Successive chromatographic procedures made it possible to isolate thrombocytopoietin from the serum of thrombocytopenic rats. The following steps were taken: DEAE-cellulose phosphate chromatography, Sephadex chromatography, exclusion chromatography on DEAE-Sephadex A-50 gel. The apparent molecular weight of thrombocytopoietin was about 48,000 daltons. Like erythropoietin, thrombocytopoietin is a glycoprotein, its molecular weight is similar. A single form is obtained only when the different purification steps last less than 10 days. Beyond that time, partial degradation may occur.