Accurate, robust, and reliable methods for your protein analysis
Bradford vs. BCA: What's the Difference?
Quantifying protein concentration accurately is the foundational first step for most downstream applications. The choice between the Bradford and BCA assays depends heavily on your sample composition, specifically regarding interfering substances and required sensitivity.
Feature
Bradford Assay
BCA Assay
Principle
Relies on Coomassie Brilliant Blue G-250 binding to basic and aromatic amino acids in acidic conditions, shifting absorbance from 465 nm (red-brown) to 595 nm (blue).
Utilizes an alkaline environment where proteins reduce Cu²⁺ to Cu⁺ (Biuret reaction). The resulting Cu⁺ chelates with bicinchoninic acid to form a purple complex (562 nm).
Sensitivity
Offers superior low-end sensitivity for detecting minute protein amounts, effectively measuring concentrations down to 1–20 μg/mL.
Slightly less sensitive at the extreme low end, but provides a broader, highly linear working range (typically 25–2000 μg/mL).
Compatibility
Highly susceptible to interference from chemical additives. High concentrations of detergents, buffers, and reducing agents can disrupt the assay.
Exceptional tolerance to a vast array of surfactants, cell lysis buffers, and detergents, thanks to its robust two-step mechanism.
We have both!
Whether you need the rapid simplicity of Bradford or the robust detergent compatibility of BCA, iNtRON provides highly optimized, reliable solutions tailored for your exact workflow.
Choosing the right assay depends heavily on your sample composition. PRO-MEASURE™ (Bradford) is ideal for fast, general-purpose quantification with minimal background, while SMART™ BCA offers highly uniform binding and detergent compatibility, boasting a reaction speed up to 20% faster than conventional BCA kits.
✓ PRO-MEASURE™ (Bradford)
A rapid and sensitive method utilizing Coomassie Brilliant Blue G-250. It provides fast results within 10 minutes at room temperature.
✓ SMART™ BCA
Based on bicinchoninic acid (BCA) for the colorimetric detection of Cu+ reduced by protein. Highly robust against detergents (e.g., SDS, Triton X-100) and provides excellent linearity.
PRO-MEASURE™ Protein Measurement Solution utilizes the Bradford method for quick and reliable protein quantification. The assay provides a color change from brown to blue (595 nm) in response to protein concentration. Highly sensitive and features a very short reaction time (within 10 mins) without heating.
The SMART™ BCA Protein Assay Kit uses bicinchoninic acid to measure protein concentration with high precision. It handles detergent-rich samples seamlessly and ensures excellent reproducibility (CV < 5%). Up to 20% faster than conventional BCA kits. Suitable for microplate high-throughput formats.
