Lowry Assay Calculator

Calculate protein concentration from Lowry assay with automatic standard curve fitting

Standard Curve Data (BSA)

Concentration (µg/mL)Absorbance (750nm)

Sample Measurement

Sample Concentration

166.0 µg/mL

Standard Curve Parameters

Equationy = 0.002215x + 0.0124
0.9998
CorrelationExcellent

Important Notes

  • • Read absorbance within 30 minutes of color development
  • • Linear range typically 5-100 µg/mL
  • • Reducing agents interfere with the assay

About Lowry Assay

The Lowry protein assay is a biochemical assay for determining the total level of protein in a solution. It combines the Biuret reaction (Cu²⁺ binding to peptide bonds) with Folin-Ciocalteu reagent reduction by aromatic residues.

  • Detection range: 5-100 µg/mL (standard), 1-25 µg/mL (micro)
  • Wavelength: 750 nm (or 660 nm)
  • Advantages: High sensitivity, well-established method
  • Limitations: Time-consuming, subject to interference