Invitrogen™ Qubit™ Protein Assay Kit

The Invitrogen™ Qubit™ Protein Assay Kits provide fast, accurate, and highly selective quantification of protein concentration using fluorescence-based detection. Designed for use with Qubit Fluorometers, these assays offer superior accuracy compared to traditional absorbance-based methods, especially in the presence of contaminants such as nucleic acids, salts, and reducing agents.

Two assay formats are available to support diverse protein quantification needs:

• Qubit Protein Assay Kit: Ideal for standard protein quantification across a concentration range of 12.5 μg/mL to 5 mg/mL
• Qubit Protein Broad Range (BR) Assay Kit: Designed for higher concentration samples, with an extended range of 0.1 mg/mL to 20 mg/mL, allowing direct measurement of many samples without dilution

Both assays provide highly reproducible and accurate protein quantification for applications in proteomics, molecular biology, biotechnology, and life sciences research.

Key Features

Highly Accurate Fluorescence-Based Protein Quantification

• Selective detection of proteins with minimal interference from contaminants
• More accurate than UV absorbance methods
• Ideal for precise protein concentration measurement

Broad Dynamic Range Options

• Standard assay: 12.5 μg/mL to 5 mg/mL
• Broad Range assay: 0.1 mg/mL to 20 mg/mL
• Supports both low and high protein concentration samples

Fast and Easy Workflow

• Requires only 1–20 μL sample volume
• Minimal preparation steps
• Rapid fluorescence measurement using Qubit Fluorometer

High Selectivity and Contaminant Tolerance

Compatible with common contaminants such as:

• Reducing agents (DTT, β-mercaptoethanol)
• Salts
• Free nucleotides
• Amino acids
• Nucleic acids
• Detergents (BR Assay Kit)

Ready-to-Use Kit Components

Includes:

• Protein assay reagent
• Assay buffer
• Protein standards
• Simplified calibration and quantification workflow

Applications

The Qubit Protein Assay Kits are ideal for a wide range of applications, including:

• Protein concentration measurement for molecular biology workflows
• Proteomics research
• Quantification of purified proteins
• Measurement of protein concentration in lysates, serum, and plasma
• Protein quantification before downstream assays
• Biotechnology and pharmaceutical research
• Quality control in protein purification workflows

Instrument Compatibility

Compatible with:

• Qubit™ 1.0 Fluorometer
• Qubit™ 2.0 Fluorometer
• Qubit™ 3 Fluorometer
• Qubit™ 4 Fluorometer
• Qubit™ Flex Fluorometer

(BR Assay Kits are optimized for Qubit 4 and Qubit Flex Fluorometers)

Technical Specifications

Advantages for Molecular Biology and Proteomics Laboratories

• Highly accurate protein quantification with minimal interference
• Broad dynamic range supports diverse sample types
• Rapid and simple workflow improves laboratory efficiency
• Ideal for genomics, proteomics, and molecular biology workflows
• Compatible with Qubit Fluorometers used in NGS and sequencing laboratories
• Reliable results for critical research applications

The Invitrogen™ Qubit™ Protein Assay Kits and Protein Broad Range Assay Kits provide a fast, accurate, and reliable solution for fluorescence-based protein quantification. With superior sensitivity, broad dynamic range options, and compatibility with Qubit Fluorometers, these kits are essential tools for proteomics, molecular biology, biotechnology, and genomics laboratories requiring precise protein concentration measurement for research and analytical workflows.