Description

Bradford Protein Quantification Assay Kit is a rapid colorimetric protein assay designed for accurate protein concentration measurement in biological samples. During routine protein preparation, inaccurate protein quantification can lead to inconsistent sample loading, unreliable Western blot results, and poor reproducibility in SDS-PAGE or protein analysis workflows. This Bradford protein assay kit provides a simple and reliable method to determine total protein concentration by measuring the absorbance change caused by Coomassie Brilliant Blue G-250 binding to proteins.

Based on the Bradford assay method, the kit utilizes Coomassie Brilliant Blue G-250 dye under acidic conditions. When the dye binds to proteins, the absorption maximum shifts from approximately 465 nm to 595 nm, and the increase in A595 absorbance is proportional to protein concentration within the linear detection range. Protein concentration can be calculated using a BSA standard curve, making it suitable for routine protein quantification applications.

Bradford Protein Quantification Assay Kit provides a fast and convenient workflow compatible with microplate readers and spectrophotometers. Compared with traditional protein concentration determination methods, this protein assay kit offers simple operation, rapid detection, and good compatibility with many commonly used reducing agents, making it suitable for Western blot sample preparation, SDS-PAGE analysis, immunoprecipitation workflows, and general biochemical research.

Specifications

Product Name	Bradford Protein Quantification Assay Kit
Product Type	Bradford Protein Assay Kit
Assay Principle	Coomassie Brilliant Blue G-250 Dye Binding Method
Detection Method	Colorimetric Protein Assay
Detection Wavelength	595 nm
Standard Protein	Bovine Serum Albumin (BSA)
Capacity	1000 Assays
Applications	Protein Quantification, Western Blot, SDS-PAGE, Protein Analysis
Sample Types	Cell Lysates, Tissue Extracts, Purified Proteins
Storage	2–8 °C
Shelf Life	12 Months

Features

Rapid protein quantification: Provides a fast Bradford assay workflow with color development and absorbance measurement completed within minutes.
Coomassie Brilliant Blue G-250 based detection: Uses the classic Bradford protein assay method for reliable protein concentration determination.
595 nm colorimetric detection: Quantifies protein concentration by measuring A595 absorbance using a microplate reader or spectrophotometer.
BSA standard curve calculation: Includes BSA protein standard for generating accurate protein concentration calibration curves.
Simple experimental workflow: Requires minimal sample preparation and is suitable for routine laboratory protein analysis.
Reducing agent compatibility: Compatible with commonly used reducing agents including β-mercaptoethanol and DTT within recommended concentrations.

Applications

Bradford Protein Quantification Assay Kit is widely used for protein concentration measurement in molecular biology, cell biology, and biochemical research workflows.

Western Blot Protein Quantification: Determines protein concentration before SDS-PAGE loading to improve sample normalization and experimental consistency.
SDS-PAGE Sample Preparation: Provides accurate protein measurement for electrophoresis experiments requiring equal protein loading.
Cell Lysate Protein Analysis: Measures total protein concentration from cultured cell extracts and biological samples.
Tissue Protein Extraction: Quantifies protein concentration from animal tissue lysates for downstream biochemical studies.
Protein Purification Analysis: Determines protein recovery and concentration during purification workflows.
Immunoprecipitation (IP) and Co-IP: Supports protein normalization before antibody-based enrichment experiments.
Microplate Reader Protein Assay: Suitable for high-throughput protein concentration analysis using 96-well plates.
General Biochemical Research: Used for routine total protein measurement and protein sample characterization.

Protocol Overview

The Bradford protein assay provides a simple workflow for protein concentration determination using a BSA standard curve.

Prepare BSA standards and dilute protein samples appropriately.
Prepare 1× Bradford working solution by diluting concentrated G-250 staining reagent.
Add protein standards or samples into a microplate or cuvette.
Add Bradford working reagent and incubate at room temperature for color development.
Measure absorbance at 595 nm and calculate protein concentration using the standard curve.

For accurate measurement, avoid excessive concentrations of detergents. High levels of SDS, Triton X-100, or Tween detergents may interfere with Bradford dye binding and affect protein concentration calculation.

Ordering Information

SKU	Product	Size
AP0561	Bradford Protein Quantification Assay Kit	1000 Assays

FAQ

What is the principle of the Bradford protein assay?

The Bradford assay is based on the binding of Coomassie Brilliant Blue G-250 dye to proteins under acidic conditions. Protein binding changes the dye absorption spectrum, producing increased absorbance at 595 nm that is proportional to protein concentration.

What wavelength is used for Bradford protein quantification?

Bradford protein quantification is typically measured at 595 nm using a microplate reader or spectrophotometer. The absorbance value is used to calculate protein concentration based on a BSA standard curve.

Can Bradford Protein Quantification Assay Kit be used before Western blot?

Yes. Bradford protein assay is commonly used to determine protein concentration before Western blot and SDS-PAGE experiments, allowing researchers to normalize protein loading between samples.

What protein standard is used for Bradford assay?

Bovine Serum Albumin (BSA) is commonly used as the protein standard for Bradford assays. The included BSA standard can be used to generate a calibration curve for protein concentration calculation.

Which substances may interfere with Bradford protein assay?

High concentrations of detergents may interfere with Bradford dye binding. SDS should generally be below 0.1%, Triton X-100 below 0.1%, and Tween detergents below recommended limits for accurate detection.

Is Bradford assay compatible with reducing agents?

Bradford protein quantification has good compatibility with some reducing agents. β-mercaptoethanol and DTT can generally be tolerated within appropriate concentrations, but sample composition should be considered during assay optimization.