Thermo Fisher Scientific Pierce 660nm Protein Assay Kit

Thermo Scientific™ Pierce™ 660nm Protein Assay Kit

The Pierce 660-nm Protein Assay is a ready-to-use, detergent- and reducing agent-compatible reagent designed for rapid and accurate total protein quantitation compared to a protein standard. The assay provides greater linearity than Coomassie-based Bradford assays and is compatible with higher concentrations of detergents, reducing agents, and other common reagents.

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Features

• Compatibility: Works with a broader range of detergents and reducing agents than other dye-based assays
• Ready-to-use: Single reagent, simple mix-and-read protocol, no reagent preparation required
• Linearity: Produces more linear standard curves than the Bradford method
• Assay format: Suitable for test tubes or microplates
• Sample volume: Requires only 10 μL (microplate) or 100 μL (test tube)
• Storage: Room temperature stable

Additional Information

The optional Ionic Detergent Compatibility Reagent (IDCR) extends detergent compatibility, making this one of the few assays suitable for samples containing Laemmli SDS sample buffer with bromophenol blue. Although the Pierce 660-nm Protein Assay shows higher protein-to-protein variation (37%) than the BCA Protein Assay, its single-reagent simplicity and broad compatibility make it ideal for routine applications. The assay can be performed in both test tube and microplate formats.

How the Pierce 660-nm Assay Detects Protein

The assay is based on the binding of a proprietary dye-metal complex to protein under acidic conditions, causing a shift in absorption maximum to 660 nm. The dye-metal complex changes from reddish-brown to green upon protein binding due to deprotonation at low pH, facilitated by interactions with positively charged amino acid residues (histidine, arginine, lysine) and, to a lesser extent, tyrosine, tryptophan, and phenylalanine.
The resulting color is stable and increases proportionally with protein concentration, even in the presence of detergents and reducing agents incompatible with Bradford and BCA assays.

Related Products

• Pierce 660-nm Protein Assay Reagent
• Ionic Detergent Compatibility Reagent for Pierce 660-nm Protein Assay Reagent

Specifications