Measuring protein concentration

Accurately quantifying total protein concentration is a key step in most experiments and workflows involving isolation, separation, and analysis of proteins. We offer a variety of assay reagents, kits, and standards for protein quantitation by fluorescent or colorimetric detection with fluorometers, spectrophotometers, and plate readers.

Additionally, our products are offered with dilution-free protein standards for added ease-of-use with reduced set up time when generating your standard curve. Dilution-Free protein standards are a set of prediluted standards, packaged in a multichannel pipette compatible format which allows you to easily transfer a full dilution series to your microplate, at once.

Selection guide  Technical handbook

Which protein assay is right for you?

 packaging, reagent, and dilution-free tubes for Bradford assay
NEW Pierce Bradford Plus Protein Assay Kit with Dilution-Free BSA Protein Standard		packaging, reagents, and dilution-free tubes for BCA protein assay
NEW Pierce BCA Protein Assay Kit with Dilution-Free BSA Protein Standards		packaging, reagents, and dilution-free tubes for BCA protein assay
NEW Pierce Dilution-Free Rapid Gold BCA Protein Assay Kit		packaging and reagents for qubit assay
Qubit Protein Broad Range Assay

Choose when

  • Speed and ease-of-use are important
  • Accuracy and reproducibility are important
  • Accuracy and reproducibility are important
  • Speed and ease-of-use are important
  • Compatibility and convenience are important
  • High-throughput is not important
Best-in-Class Accuracy (low protein-protein variation) ✓✓✓
Broad Dynamic Range (>2 mg/mL wide)  ✓✓
Fast (≤ 15 min.)✓ ✓✓
Dilution-Free Standard Curve Preparation✓✓✓✓

Dilution-Free Sample Preparation

  ✓✓

High-Throughput (compatible with microplate format)

✓✓✓ 
Compatible with Detergents ✓✓✓

Compatible with Reducing Agents

✓  ✓

Automatic Concentration Calculations with Qubit 4

   ✓
Automatic Concentration Calculations with SkanIt Software*✓✓✓ 
*Skan it software available for Multiskan FC, Multiskan SkyHigh, and Varioskan LUX microplate readers. Learn more

We now offer Dilution-Free products, comprising both protein assays and protein standards that make protein quantification easy, fast, and accurate. Pierce Dilution-Free products allow you to minimize tedious dilutions and pipetting errors in your protein assays, delivering accurate results while reducing assay setup time by up to 80%. Learn more about our dilution-free assays.

Overview of assays

packaging, reagents, and dilution-free tubes for BCA protein assaypackaging, reagent, and dilution-free tubes for Bradford assaypackaging and reagents for qubit assay

BCA Assays

Copper-based protein assays, including the bicinchoninic acid (BCA) and Lowry methods.

  • Compatibile with most surfactants—even if present in the sample at concentrations up to 5%
  • Linear response curve (R2 > 0.95)
  • Less protein–protein variation than the Coomassie dye–based assays
  • Dilution-free BSA protein standards for faster assay time and effortless standard curve generation

View all BCA protein assays

 

Bradford Assays

Coomassie dye-binding assays for fast and simple protein quantification.

  • Typically faster and easier to perform compared to most protein assays
  • Performed at room temperature
  • Compatible with most salts, solvents, buffers, thiols, reducing substances, and metal-chelating agents
  • Dilution-free BSA protein standards for faster assay time and effortless standard curve generation

View all Bradford assays and reagents

 

Fluorescent Protein Assays

Fluorescence-based protein quantification detection methods provide superior sensitivity.

  • Excellent sensitivity, requiring less protein sample for quantitation
  • Timing is not a critical factor, so the assays can be adapted for automated handling in high-throughput applications
  • Good protein-to-protein variation

View all fluorescent protein assays

 

Related products and downstream applications

Resources

Pierce Protein methods – an encyclopedia of articles about protein analysis

Protein assay technical guide – tools and reagents for improved quantitation of total or specific proteins.

Protein assay compatibility table – summarizes compatible substances for several popular protein assays.

Protein Analysis Learning Center – resources for different protein analysis techniques

Protein Biology Application Notes – journal-style articles based on research applications and proof-of-concept experiments

Liberate yourself with Pierce Dilution-Free protein assays

For Research Use Only. Not for use in diagnostic procedures.