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Description
The Pierce BCA Protein Assay Kit is a high-precision, detergent-compatible protein assay for determination of protein concentration. Pierce BCA reagents provide accurate determination of protein concentration with most sample types encountered in protein research. The Pierce BCA assay can be used to assess yields in whole cell lysates, affinity-column fractions, purified proteins samples, as well as to monitor protein contamination in industrial applications. Compared to most dye-binding methods, the BCA assay is affected much less by protein compositional differences, providing greater concentration accuracy.
Kits are available with or without Pierce Dilution-Free BSA Protein Standards, which are a set of seven pre-diluted BSA standards, packaged in a multichannel pipette-friendly tubestrip. The tubestrip includes a single empty tube that enables users to add their own sample buffer for the purpose of blank subtraction.
The Pierce BCA Protein Assay Kit is a high-precision, detergent-compatible protein assay for determination of protein concentration. Pierce BCA reagents provide accurate determination of protein concentration with most sample types encountered in protein research. The Pierce BCA assay can be used to assess yields in whole cell lysates, affinity-column fractions, purified proteins samples, as well as to monitor protein contamination in industrial applications. Compared to most dye-binding methods, the BCA assay is affected much less by protein compositional differences, providing greater concentration accuracy.
Kit options are available that include Pierce Dilution-Free BSA Protein Standards, which are a set of seven pre-diluted BSA standards, packaged in a multichannel pipette-friendly tubestrip. The tubestrip includes a single empty tube that enables users to add their own sample buffer for the purpose of blank subtraction.
Features of the BCA Protein Assay Kit include:
- Colorimetric—estimate visually or measure with a standard spectrophotometer or plate reader at 562 nm
- Accurate—exhibits half the protein-to-protein variation observed with dye-binding methods (Bradford)
- Compatible—unaffected by typical concentrations of most ionic and non-ionic detergents
- Short assay time—30-min incubation; much easier and four times faster than classical Lowry methods
- Wide assay range—linear working range for BSA of 20 to 2000 μg/mL
- Sensitive—detect down to 5 μg/mL with enhanced protocol
- No more serial dilutions—kit options include Dilution-Free BSA Protein Standards which eliminate the need to perform serial dilutions when generating a standard curve
How the assay works
The BCA Protein Assay combines the well-known reduction of Cu2+ to Cu1+ by protein in an alkaline medium with the highly sensitive and selective colorimetric detection of the cuprous cation (Cu1+) by bicinchoninic acid (BCA). The first step is the chelation of copper with protein in an alkaline environment to form a light blue complex. In this reaction, known as the biuret reaction, peptides containing three or more amino acid residues form a colored chelate complex with cupric ions in an alkaline environment containing sodium potassium tartrate.
In the second step of the color development reaction, BCA reacts with the reduced (cuprous) cation that was formed in step one. The intense purple-colored reaction product results from the chelation of two molecules of BCA with one cuprous ion. The BCA/copper complex is water soluble and exhibits a strong linear absorbance at 562 nm with increasing protein concentrations. The complex is approximately 100 times more sensitive (lower limit of detection) than the pale blue color of the first reaction.
The reaction is strongly influenced by four amino acid residues (cysteine, cystine, tyrosine, and tryptophan) in the amino acid sequence of the protein. However, unlike Coomassie dye-binding methods (i.e., Bradford), the universal peptide backbone also contributes to color formation, helping to minimize variability caused by protein compositional differences.
Specifications
Specifications
| Concentration | BSA: 0.125, 0.25, 0.5, 0.75, 1, 1.5, and 2 mg/mL |
| Content And Storage | Sufficient for: 500 tube assays or 5000 microplate assays • BCA Reagent A, 2 x 500 mL • BCA Reagent B, 25 mL • Dilution-Free BSA Protein Standards (0.125-2 mg/mL), 4 x 1 mL 8-channel tubestrip Store at room temperature. Store Dilution-Free BSA Protein Standards at 4°C after opening. |
| Assay | BCA Assay |
| Detection Method | Colorimetric |
| Product Line | Pierce |
| Product Type | Protein Quantitation Assay |
| Specificity | Not Target-specific |
| Sufficient For | 500 Tube Assays or 5000 Microplate Assays |
| For Use With (Application) | Solution-based Detection, Absorbance |
| For Use With (Equipment) | Spectrophotometer, Microplate Reader |
| Show More |
Frequently Asked Questions (FAQs)
The Pierce BCA Protein Assay combines the well-known reduction of Cu2+ to Cu1+ by protein in an alkaline medium with the highly sensitive and selective colorimetric detection of the cuprous cation (Cu1+) by bicinchoninic acid (BCA). The first step is the chelation of copper with protein in an alkaline environment to form a light blue complex. In this reaction, known as the biuret reaction, peptides containing three or more amino acid residues form a colored chelate complex with cupric ions in an alkaline environment containing sodium potassium tartrate.
In the second step of the color development reaction, BCA reacts with the reduced (cuprous) cation that was formed in step one. The intense purple-colored reaction product results from the chelation of two molecules of BCA with one cuprous ion. The BCA/copper complex is water soluble and exhibits a strong linear absorbance at 562 nm with increasing protein concentrations. The complex is approximately 100 times more sensitive (lower limit of detection) than the pale blue color of the first reaction.
The reaction is strongly influenced by four amino acid residues (cysteine, cystine, tyrosine, and tryptophan) in the amino acid sequence of the protein. However, unlike Coomassie dye-binding methods (i.e., Bradford), the universal peptide backbone also contributes to color formation, helping to minimize variability caused by protein compositional differences.
Yes, the Pierce Dilution-Free BSA Protein Standards, Multichannel Pipette Compatible, 0.125-2 mg/mL can be purchased separately (Cat. No. A55863).
Pierce Dilution-Free BSA Protein Standards are provided in a convenient 8-channel tubestrip. Each tube contains 1 mL of pre-diluted BSA protein standard at each concentration required for generating a standard curve. In the Pierce BCA Protein Assay Kit with Dilution-Free BSA Protein Standards, Multichannel Pipette Compatible (Cat. No. A55864, A55865), the BSA concentrations included are 2000, 1500, 1000, 750, 500, 250, and 125 µg/mL. Each tubestrip contains one empty tube which allows the user to add their own blank solution for the purpose of background correction. This convenient format eliminates the time-consuming dilution step required for other single-concentration protein standard formats like the Pierce Bovine Serum Albumin Standard Ampules, 2 mg/mL (Cat. No. 23209).
Additionally, the tubestrips are compatible with multichannel pipettes which allows the user to easily transfer the full standard curve dilution series (including blank) to a microplate simultaneously. This minimizes pipetting time associated with traditional protein standard preparation or pre-diluted protein standards which are typically packaged in 7 separate vials, requiring the user to open each vial and pipette each standard individually.
The Pierce BCA Protein Assay Kit with Dilution-Free BSA Protein Standards (Cat. No. A55864, A55865) includes the same assay reagents (BCA Protein Assay Reagent A and BCA Protein Assay Reagent B) as the Pierce BCA Protein Assay Kit (Cat. No. 23225, 23227). The only difference between the two products is the BSA protein standard format. While the Pierce BCA Protein Assay Kit (Cat. No. 23225, 23227) includes the Pierce Bovine Serum Albumin Standard Ampules, 2 mg/mL (Cat. No. 23209), the Pierce BCA Protein Assay Kit with Dilution-Free BSA Protein Standards (Cat. No. A55864, A55865) includes BSA protein standards that are pre-diluted and packed in a convenient, multichannel pipette-friendly format. This format provides the following advantages:
-No protein standard dilution step needed
-High-throughput (multichannel pipette compatible)
-Blank tube provided for background correction
-Reduced hands-on assay time
-Reduced chances for pipetting errors
We currently do not offer bovine gamma globulin (BGG) protein standards in the same multichannel pipette compatible format as the Pierce Dilution-Free BSA Protein Standards. They are only available as Pierce Bovine Gamma Globulin Standard Ampules, 2 mg/mL (Cat. No. 23212) and Pierce Bovine Gamma Globulin Standard Pre-Diluted Set (Cat. No. 23213).
Safety and Handling
- PIERCE BCA W/ DF BSA STD
- Danger
- LONG-TERM AQUATIC HAZARD Chronic 2
- ACUTE AQUATIC Acute 1
- Serious eye damage/eye irritation Category 1
- H318-Causes serious eye damage.
- H400-Very toxic to aquatic life.
- H411-Toxic to aquatic life with long lasting effects.
- P273-Avoid release to the environment.
- P280-Wear protective gloves/protective clothing/eye protection/face protection.
- P305+P351+P338-IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.
- P310-Immediately call a POISON CENTER/doctor/.
- P391-Collect spillage.
- P501b-Dispose of contents/container in accordance with local/regional/national/international regulations.
- MIXTURE LIST-Contain: Copper (II) sulfatepentahydrate
For Research Use Only.
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