| Abstract: | Fresh and stored preparations of human pituitary somatotropin examined by different polyacrylamide gel electrophoresis techniques and by gel exclusion chromatography (Ultrogel) clearly demonstrated that the hormone undergoes a structural alteration during storage for 3 years. The formed aggregates were readily quantitated from the gel filtration profile and from polyacrylamide gel electrophoresis in the presence of sodium dodecylsulfate (SDS-PAGE). According to gel filtration the amount of aggregates in fresh and stored hormone was determined to be 2 and 10%, respectively, while SDS-PAGE indicated 6 and 14%. |
