Thermo NanoDrop One, User Manual, Page: 117 / 312

Thermo Scientific NanoDrop One User Guide 111
Measure Protein Lowry
Measure Total Protein Concentration
The Protein Lowry assay uses Folin-Ciocalteu as a colorimetric detection reagent to determine
total protein concentration in unpurified protein samples. This application is an alternative to
the other colorimetric applications for measuring dilute protein solutions or proteins in the
presence of components that exhibit significant absorbance between 200 nm and 280 nm.
This application measures absorbance at 650 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 Lowry assay
The Protein Lowry assay involves the reaction of protein with cupric sulfate in alkaline
solution, resulting in the formation of tetradentate copper-protein complexes. The
Folin-Ciocalteu reagent is effectively reduced in proportion to the chelated copper-complexes.
The water-soluble blue reaction product is measured at 650 nm and baseline-corrected using
the absorbance value at 405 nm. Pre-formulated kits of Folin-Ciocalteu reagent and CuSO
4
are available from us or a local distributor.
Measures total protein
concentration of unpurified protein
samples using a Folin-Ciocalteu
colorimetric detection reagent.
Measure Total Protein
Reported Results
Settings
Detection Limits