Enter your Absorbance at 595 nm, Standard Curve Slope (m), Standard Curve Intercept (b), Dilution Factor, and Protein Molecular Weight into the Bradford Assay Calculator to find your sample's Protein Concentration, adjusted Concentration, and Molar Concentration — no manual curve math required.
Protein Concentration
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Concentration
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Molar Concentration
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Prepare a series of BSA (bovine serum albumin) standards in the same buffer as your samples, typically ranging from 0.1 to 1.4 mg/mL. Use at least 5-6 different concentrations to create a reliable standard curve.
Bradford assay results are typically expressed in mg/mL or µg/mL. The standard curve is usually plotted with concentration in mg/mL on the x-axis and absorbance at 595 nm on the y-axis.
Multiply your calculated concentration by the dilution factor. For example, if you diluted your sample 1:10 (dilution factor = 10) and calculated 0.5 mg/mL, your actual concentration is 5.0 mg/mL.
Bradford assay typically detects protein concentrations between 0.02-1.4 mg/mL (20-1400 µg/mL). The linear range is usually 0.1-0.9 mg/mL for optimal accuracy.
Common interference factors include detergents, reducing agents, high salt concentrations, and basic pH buffers. Ensure your samples and standards are in compatible buffers for accurate results.
Plot absorbance (595 nm) vs. protein concentration for your standards. Use linear regression to determine the slope (m) and intercept (b) for the equation y = mx + b, where y is absorbance and x is concentration.
BSA (bovine serum albumin) is the most commonly used standard protein for Bradford assay. It's stable, pure, and provides consistent results across different laboratories.
The blue color complex in Bradford assay is stable for about 1 hour at room temperature. Read absorbance between 5 minutes and 1 hour after adding the reagent for best results.