Lowry Protein Assay - UV Vis Spectroscopy
Spectrophotometric Quantification of the Total Protein Content in Biological Samples
This spectroscopy application note shows how a Lowry Protein assay is used to determine the total protein content in biological samples. For more information proceed to download the method information below.
How is the Lowry assay determined spectrophotometrically?
Lowry assay is used to quantify the total protein content in biological samples. In this assay, cupric ions Cu2+ are reduced to Cu1+ in the presence of peptide bonds at an alkaline pH. In a second step, the reduction of the Folin Ciocalteu Reagent (phosphomolybdic / phosphotungstic acid) by amino acids produces a blue color. The Lowry method needs more preparation but results in a higher sensitivity in comparison to other protein assays. Samples in the range of 5 to 200 μg/mL are measured at 750 nm and quantified based on the standard curve.
