Solarbio BCA Protein Assay Kit

The BCA (Bicinchoninic Acid) Protein Assay Kit is a widely used method for the quantification of protein concentrations in a sample. This assay relies on the colorimetric detection of copper(II) ions reduced by proteins under alkaline conditions. The intensity of the resulting purple color is proportional to the protein concentration, allowing for precise quantification.

Here is a general guide on how to use a BCA Protein Assay Kit:

Materials Required:

1. BCA Protein Assay Kit
2. Protein samples (standard solutions or unknown samples)
3. Microplate or cuvettes
4. Micropipettes and tips
5. Microplate reader or spectrophotometer
6. Distilled water

Procedure:

1. Preparation of Protein Standards:
   • Prepare a series of protein standards with known concentrations. These standards will be used to create a standard curve for quantification.
2. Preparation of Samples:
   • Dilute your protein samples to a concentration within the range of the standards. It’s important to have samples within the linear range of the assay for accurate quantification.
3. Preparation of BCA Working Reagent:
   • Mix the BCA Reagent A (Bicinchoninic Acid solution) and BCA Reagent B (Copper(II) sulfate solution) in a 50:1 ratio. Ensure thorough mixing.
4. Incubation:
   • Add the BCA Working Reagent to your standards and samples, and then incubate the reaction mixture at a suitable temperature (commonly 37°C) for 30 minutes. During this time, proteins in the samples will reduce the copper ions, forming a purple-colored complex.
5. Measurement:
   • After incubation, measure the absorbance of each well at a wavelength around 562 nm using a microplate reader or spectrophotometer. The absorbance is directly proportional to the protein concentration.
6. Creation of Standard Curve:
   • Plot the absorbance values of the standards against their known concentrations to create a standard curve. This curve will be used to determine the protein concentrations of unknown samples.
7. Quantification of Unknown Samples:
   • Measure the absorbance of your unknown samples and use the standard curve to determine their protein concentrations.
8. Data Analysis:
   • Calculate the protein concentrations based on the standard curve. Most microplate readers have software that can automate this process.
9. Results:
   • Report the protein concentrations of your samples in the appropriate units (e.g., mg/mL) based on the BCA assay.

It’s important to follow the specific instructions provided by the manufacturer of the BCA Protein Assay Kit, as the exact protocol may vary between kits. Additionally, ensure that all reagents are properly stored, and the assay is performed under the recommended conditions for accurate and reliable results.

The BCA Protein Assay Kit is based on  the protein reduces Cu2+ to Cu+ and the principle that BCA forms a purple-blue complex with Cu1+ under alkaline conditions, followed by detecting absorbance at 562nm and comparing with the standard curve to quantify the protein.