Comparison of colorimetric m ethods for the quantification of model proteins in aqueous two-phase systems
Heinisch, Sandra L.
- Publisher: Cambridge, MA : Elsevier Academic Press
Aqueous two-phase system | BCA assay | Bradford assay | Colorimetric analysis | Protein quantification | citrate sodium | citric acid | dextran | drug analysis | macrogol | macrogol derivative | phosphate | potassium derivative | potassium dihydrogen phosphate | water | alkalinity | bicinchoninic acid assay | chemical phenomena | chemistry | colorimetry | comparative study | intermethod comparison | limit of quantitation | molecular weight | priority journal | procedures | protein binding | protein determination | viscosity | analysis | Citrates | Phosphates | Polyethylene Glycols | Potassium Compounds | Proteins
In the current study, the quantification of different model proteins in the presence of typical aqueous two-phase system components was investigated by using the Bradford and bicinchoninic acid (BCA) assays. Each phase-forming component above 1 and 5 wt% had considerable effects on the protein quantification in both assays, respectively, resulting in diminished protein recoveries/absorption values by increasing poly(ethylene glycol) (PEG)/salt concentration and PEG molecular weight. Therefore, a convenient dilution of both components (up to 1 and 5 wt%) before protein quantification is recommended in both assays, respectively, where the BCA assay is favored in comparison with the Bradford assay.