Coomassie blue sodium dodecyl sulfate polyacrylamide

Figure 10.7 Polypeptide patterns of material associated with lipid globules of cow s milk. The sodium dodecyl sulfate-polyacrylamide gel in (a) was stained with coomassie blue, and polypeptides in the gel in (b) were visualized with the more sensitive silver stain (Merril ef at. 1981). In both (a) and (b) the left lane contains proteins extracted directly from washed milk...

In Experiment 4, your sample of a-lactalbumin extracted from bovine milk was subjected along with other proteins to sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). After staining with the dye Coomassie Blue, deeply colored bands appeared on the gel wherever there was a protein. You suspected that some of the blue bands on the gel were due to a-lactalbumin. If molecular weight standards were included on the slab gel, you were able to estimate the molecular weight for a-lactalbumin and other proteins. SDS-PAGE is indeed a very effective analytical tool to achieve fractionation of protein mixtures, to analyze purity, and to estimate molecular weight, but it provides no experimental data to prove the identity... 

Figure 10. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of products of limited proteolysis of the debranching enzyme with trypsin. The molecular weights shown of the various bands were determined by the methodology described previously (26). The ratio of debrancher to trypsin was 100 to 1. The incubation was conducted for 60 minutes at 25°. The gel stain was Coomassie Brilliant Blue and the absorbance was measured at 600 nm using a Gilford gel scanner with a 0-1 O.D. chart scale (36).

Figure 6-4. Sodium dodecyl sulfate polyacrylamide gel electrophoresis pattern of normal red cell membrane proteins with Coomassie blue staining.

Schematic representations of sodium dodecyl sulfate polyacrylamide gel electrophoretic patterns of red blood cell membranes (M) and membrane skeletons (S), based on work by Fairbanks and Steck. Proteins are stained with Coomassie blue (CB) and sialoglycoproteins with periodic acid-Schiff (PAS). GPA, GPB, and GPC are glycophorin A. B, and C, respectively G3PD is glyceraldehyde-3-phosphate dehydrogenase. (GPA)2 and (GPB)2 are dimers, and GPA-GPB is a heterodiraer. [Reproduced with permission from J. B. Stanbury, J. B. Wyngaarden, D. S. Fredrickson, et al. (Eds.), The Metabolic Basis of Inherited Disease, 5th ed. McGraw-Hill, New York, 1983.]...

Fig. 2. The representative results for checking quality of recombinant proteins checked by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) gel. Two microgram of SH2 recombinant proteins were loaded on 10% SDS-PAGE gel, and the gels were stained with Coomassie Brilliant Blue.

Fig. 1. Sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis (PAGE) analysis of expression and purification of recombinant protein. Ten-microliter aliquots were withdrawn at each step of the purification and loaded on a 12% SDS-PAGE gel in a Mini Protean III cell gel electrophoresis unit (Bio-Rad). The detection was performed with Coomassie blue staining. MW, low range (14-98 kDa) molecular weight marker (Bio-Rad).

Fig. 2. Gel filtration chromatography. Fractions collected from a HiLoad 26/60 Superdex 75 pg column were resolved in a 15-25% gradient sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis (PAGE) gel and stained with Coomassie blue.

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