Protein Quantification Assays

Accurate protein quantification is a critical first step in many biochemical and molecular biology workflows, including SDS-PAGE, Western blotting, and enzyme assays. Our Protein Quantification Kits provide fast, reliable, and sensitive methods for determining total protein concentration in a wide range of biological samples.

Choose from two widely used, colorimetric protein quantification methods—Bicinchoninic Acid (BCA) and Bradford Coomassie-based assays—each offering distinct advantages depending on your sample type, buffer composition, and sensitivity requirements.

Key Features:

• Sensitive, reproducible quantification of total protein
• Simple colorimetric readout using standard plate readers or spectrophotometers
• Optimized for use with a variety of biological samples and buffers
• Compatible with high-throughput and small-volume formats
• Rapid protocols with stable endpoints

Bicinchoninic Acid (BCA) Protein Assay Kit

The BCA Protein Assay is a highly sensitive, copper-based colorimetric assay ideal for routine quantification of total protein in samples containing detergents and other interfering substances. In an alkaline environment, proteins reduce Cu²⁺ to Cu⁺, which then forms a purple-colored complex with bicinchoninic acid (BCA). This complex absorbs strongly at 562 nm, and its intensity increases linearly with protein concentration.

Advantages:

• High tolerance for common detergents and buffers
• Linear detection range with excellent sensitivity
• Stable, water-soluble endpoint for up to several hours

Ideal for:

• General protein quantification, detergent-rich samples, Western blot prep

Bradford Protein Assay Kit

The Bradford Protein Assay is a fast and sensitive dye-binding method using Coomassie Brilliant Blue G-250, which shifts from brown (488 nm) to blue (595 nm) upon binding to proteins. The color intensity is proportional to protein concentration, with a stable signal for up to an hour at room temperature.

Advantages:

• Rapid results within 5 minutes
• Higher sensitivity than the Lowry method
• Simple, single-reagent format

Ideal for:

• High-throughput protein screening, low-volume samples, routine lab use

Applications:

These protein assay kits are suitable for a wide range of research needs, including:

• Sample normalization for SDS-PAGE and Western blotting
• Monitoring protein expression or purification
• Measuring protein yield from cell and tissue lysates
• Quality control in proteomics and protein-based assays

Learn more about these Protein Quantification Assays here. 

If you have any questions, or need help selecting the product that is right for you, please contact us.