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

Product Name	Lowry Protein Assay Kit
SKU	RP0121
Product Type	Lowry Protein Quantification Assay Kit
Detection Method	Folin-Ciocalteu Colorimetric Protein Assay
Detection Range	5–500 μg/mL Protein
Detection Wavelength	A650 nm
Detection Format	96-Well Microplate Reader or Spectrophotometer
Standard	BSA Protein Standard (5 mg/mL)
Applications	Protein Quantification, Western Blot Sample Preparation, SDS-PAGE, Biochemical Research
Storage	BSA Standard: 2–8°C or -20°C; Other Reagents: Room Temperature

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.

Ordering Information

SKU	Product	Size
RP0121	Lowry Protein Assay Kit	1000 Assays

FAQ

What is a Lowry Protein Assay Kit used for?

Lowry Protein Assay Kit is used for quantitative measurement of total protein concentration in biological samples. It is commonly applied before Western blot, SDS-PAGE, immunoprecipitation, and biochemical protein analysis workflows.

How does the Lowry protein assay work?

The Lowry protein assay uses a two-step reaction. Proteins first react with copper ions under alkaline conditions to form protein-copper complexes. These complexes then reduce Folin-Ciocalteu reagent to generate a blue color signal proportional to protein concentration.

What is the detection range of this Lowry protein quantification kit?

This Lowry Protein Assay Kit provides a protein detection range of 5–500 μg/mL, making it suitable for common cell lysates, tissue extracts, and protein samples.

Can Lowry assay be used for Western blot sample preparation?

Yes. Lowry protein quantification is commonly used before Western blot experiments to normalize protein loading amounts and improve experimental consistency.

What protein standard is included in the kit?

The kit includes a BSA protein standard at 5 mg/mL, which can be diluted to prepare a standard curve for protein concentration calculation.

What substances interfere with Lowry protein assays?

Phenolic compounds, citrate, sulfhydryl-containing reagents, and differences in amino acid composition between proteins may affect color development and influence quantification accuracy.

Can Lowry protein assay be detected using a microplate reader?

Yes. The assay is compatible with 96-well microplate detection using a plate reader at A650 nm, as well as measurement using a conventional spectrophotometer.