Optimization of the cydex blue assay: A one-step colorimetric protein assay using cyclodextrins and compatible with detergents and reducers
Fig 3
Comparison of the effects of alpha and beta cyclodextrin.
Panel A: effect of increasing concentrations of cyclodextrin on the background absorbance of the assay. Different concentrations of alpha-cyclodextrin (black curve) and beta-cyclodextrin (blue curve) were added to the Bradford reagent and the interference measured. Panel B: effects of cyclodextrins in the Bradford assay. Different concentrations of cyclodextrins were used in a protein assay containing 10 μl SDS buffer per ml of assay. Black: control: no SDS buffer, no cyclodextrin. Blue: 2.5 mg alpha-cyclodextrin / ml of Bradford reagent (CD/SDS molar ratio: 3.65). Purple: 5 mg alpha-cyclodextrin / ml of Bradford reagent (CD/SDS molar ratio: 7.3). Green: 2.5 mg beta-cyclodextrin / ml of Bradford reagent (CD/SDS molar ratio: 3.17).