Thermo NanoDrop One, User Manual, Page: 125 / 312

Thermo Scientific NanoDrop One User Guide 119
Measure Protein Pierce 660
Measure Total Protein Concentration
The Protein Pierce 660 assay uses a proprietary protein binding material as a colorimetric
detection reagent to determine total protein concentration in unpurified protein samples.
This application is suitable for protein solutions that contain high concentrations of
detergents, reducing agents and other commonly used reagents. The Pierce 660 application
measures absorbance at 660 nm and uses a standard curve to calculate protein concentration
(see
Working with Standard Curves for more information). A single-point baseline correction
is applied.
Theory of Protein Pierce 660 assay
The Protein Pierce 660 assay is based on the binding of a proprietary dye-metal complex to
protein in acidic conditions that causes a shift in the dye’s absorption maximum, which is
measured at 660 nm. The dye-metal complex is reddish-brown and changes to green upon
protein binding. The color change is produced by deprotonation of the dye at low pH
facilitated by interactions with positively charged amino acid groups in proteins. The dye
interacts mainly with basic residues in proteins such as histidine, arginine and lysine and to a
lesser extent tyrosine, tryptophan and phenylalanine. The reaction product is measured at
660 nm and baseline-corrected using the absorbance value at 750 nm.
Measures total protein
concentration of unpurified protein
samples using a proprietary
colorimetric detection reagent.
Measure Total Protein
Reported Results
Settings
Detection Limits