Lowry Protein Assay Kit

Description

Lowry Protein Assay Kit is a classical protein quantification assay designed for accurate measurement of total protein concentration in biological samples. During protein research workflows, inconsistent protein input amounts can affect downstream experiments such as Western blot, SDS-PAGE, immunoprecipitation, and biochemical analysis. Reliable protein concentration determination is therefore essential for sample normalization and experimental reproducibility.

This Lowry Protein Assay Kit utilizes the Folin-Ciocalteu reagent-based colorimetric protein assay method. Under alkaline conditions, proteins react with copper ions to form protein-copper complexes, which subsequently reduce Folin reagent and generate a blue color signal. The color intensity is proportional to protein concentration and can be quantified using a microplate reader or spectrophotometer.

With a detection range of 5–500 μg/mL protein, this total protein assay kit provides a reliable solution for protein concentration measurement in cell lysates, tissue extracts, and other biological samples. The included BSA protein standard enables convenient generation of standard curves for accurate protein quantification.

Specifications

Features

• Classical Lowry protein quantification method: Based on the widely used Folin-Ciocalteu chemistry for reliable total protein concentration measurement.

• Accurate colorimetric protein detection: Generates a blue color signal proportional to protein concentration for quantitative analysis.

• Wide protein detection range: Supports protein concentration measurement from 5–500 μg/mL for common biological samples.

• BSA protein standard included: Provides convenient standard curve preparation without requiring additional protein standards.

• Compatible with multiple detection platforms: Suitable for microplate readers and conventional spectrophotometers.

• Suitable for routine protein analysis workflows: Supports protein quantification before Western blot, SDS-PAGE, and other downstream applications.

Applications

Lowry Protein Assay Kit is widely used for total protein quantification in molecular biology, cell biology, and biochemical research workflows where accurate protein concentration measurement is required.

• Western Blot Protein Quantification: Determines protein concentration before SDS-PAGE loading to ensure consistent sample amounts across experimental groups.

• SDS-PAGE Sample Preparation: Provides accurate protein measurement for electrophoresis experiments and protein profile analysis.

• Cell Lysate Protein Quantification: Measures total protein concentration from cultured cell extracts after protein extraction procedures.

• Tissue Protein Extraction Analysis: Supports protein concentration determination from tissue homogenates and biological samples.

• Immunoprecipitation (IP) and Co-IP: Helps normalize protein input amounts for antibody-based enrichment experiments.

• Protein Purification Monitoring: Enables protein concentration evaluation during purification and biochemical characterization workflows.

• Microplate Protein Assay: Suitable for high-throughput protein quantification using 96-well plate formats.

• Biochemistry Research: Used for routine total protein analysis and quantitative protein studies.

Protocol Overview

The Lowry protein assay procedure includes protein-copper complex formation followed by Folin-Ciocalteu reagent reduction and color development.

• Prepare Folin reagent working solution by mixing Folin reagent A and B at a 50:1 ratio.

• Dilute BSA protein standard to prepare a standard curve.

• Add standards and diluted samples into a 96-well plate or reaction tubes.

• Add Folin reagent working solution and incubate for color development.

• Add Folin-Ciocalteu reagent and incubate at 37°C for approximately 30 minutes.

• Measure absorbance at A650 nm and calculate protein concentration based on the BSA standard curve.

Because Lowry assays depend on amino acid composition and chemical interactions, samples containing phenolic compounds, citrate, or sulfhydryl-containing reagents may interfere with color development and should be evaluated before measurement.

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