E. Goldwasser investigated erythropoietin, the hormone supporting red blood cell production. A 1977 study with T. Miyake and C. K. Kung purified human erythropoietin from urine through seven separation steps.[ref]
Purification of human erythropoietin by T. Miyake and others. Journal of Biological Chemistry252, pp.5558–5564; Abstract and byline
The work coupled protein purification to biological activity measurements. Following activity is essential when the desired protein is initially a tiny part of a complex sample: the largest protein peak need not contain the active hormone. The resulting preparation enabled experiments on an identified active material rather than an unexplained effect of crude urine.
E. Goldwasser
. Portrait identified in UChicago Medicine's research-history account, beside its description of erythropoietin purification. New to topics? Read the docs here!