This manual introduces how to use Varian DMS 90 spectrophotometer to determine protein concentration.
This document describes various laboratory procedures for determining protein concentration in solutions. It discusses the principles of measuring absorbance at 280 nm and compares this with other methods such as the biuret reaction, the Lowry assay, and the Coomassie Brilliant Blue G-250 dye-binding procedure.
| Spectral Bandwidth (280 nm) | 1.0 nm |
|---|---|
| Wavelength for Biuret Assay | 540 nm |
| Sensitivity (280 nm for Albumin) | 0.64 absorbance units per mg/mL |
| Sensitivity (Lowry Assay) | 1.67 absorbance units per mg/mL |
| Wavelength for Coomassie Assay | 595 nm |
The sensitivity is 0.64 absorbance units per mg/mL.
It is approximately three times more sensitive.
The absorbance should be measured at 595 nm.