Biomolecule Quantification
Spectrophotometry for Protein or Sugar Analysis
Explore how spectrophotometry works to quantify biomolecules like proteins or sugars. Adjust the concentration and wavelength to see how absorbance changes, and learn to create a standard curve!
Sample
Absorbance: 0.000
0.0
Observation:
Prepare your sample and select the appropriate assay type. The spectrophotometer measures how much light is absorbed by your sample at a specific wavelength.
The Science Behind Spectrophotometry
Key Concepts:
Spectrophotometry is a technique used to measure how much light a chemical substance absorbs:
- Beer-Lambert Law: Absorbance (A) is directly proportional to concentration (c): A = εlc (ε = molar absorptivity, l = path length)
- Protein Assays: Often use 280nm (aromatic amino acids) or colorimetric methods like Bradford (595nm)
- Sugar Assays: Often use colorimetric methods like DNS (540nm) or phenol-sulfuric acid (490nm)
Standard Curve:
A plot of absorbance versus known concentrations used to determine the concentration of unknown samples. The linear range depends on the assay and instrument.
