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Optimization of coomassie staining for quantitative densitometry of soybean storage proteins in gradient gel electrophoresis
Author(s) -
Kwanyuen Prachuab,
Wilson Richard F.
Publication year - 2000
Publication title -
journal of the american oil chemists' society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.512
H-Index - 117
eISSN - 1558-9331
pISSN - 0003-021X
DOI - 10.1007/s11746-000-0196-0
Subject(s) - staining , densitometry , coomassie brilliant blue , chemistry , polyacrylamide gel electrophoresis , gel electrophoresis , chromatography , electrophoresis , glycine , two dimensional gel electrophoresis , storage protein , biochemistry , biology , enzyme , proteomics , amino acid , gene , genetics , physics , quantum mechanics
Soybean ( Glycine max L. Merr., cv. Dare) protein subunits were separated by gradient gel electrophoresis and analyzed by two‐dimensional densitometry with computer‐aided volume integration. Significant differences in the time required to achieve equilibrium staining with Coomassie Blue were revealed among the various polypeptides. Bands corresponding to lipoxygenase reached staining equilibrium in 2.7 h, whereas longer periods were required for polypeptides of β‐conglycinin (5.5 to 6.7 h) and of glycinin (8.6 to 9.2 h). These differences among polypeptides could be attributed in part to changes in gradient concentration within the polyacrylamide gel. Optimal staining intensity among all soluble proteins extracted from soybean seed was reached after staining for 8 h. Shorter than optimal staining times lead to significant underestimation of parameters such as the percentage of β‐conglycinin and glycinin of total soluble protein.