Thermo Scientific Pierce BSA Protein Assay Standards are high-quality reference samples for generating accurate standard curves and calibration controls in total protein assays.
These bovine serum albumin (BSA) solutions are protein concentration reference standards for use in BCA, Bradford and other protein assay protocols. BSA is the universally accepted reference protein for total protein quantitation. The albumin standard is precisely formulated at 2mg/mL in an ultrapure 0.9% sodium chloride (saline) solution. The concentration of the stock solution is calibrated by direct comparison to purified BSA (Fraction V) from the National Institute of Standards and Technology (NIST). The product is available in three convenient package formats: 1mL glass ampules, 50mL polypropylene bottles, and complete sets containing seven ready-to-use dilutions.
- Universal – recognized as the industry standard for protein quantitation in colorimetric protein assays
- Pure and stable – supplied in ultrapure 0.9% saline solution with 0.05% sodium azide; room temperature stable
- Accurate and consistent – precisely formulated at 2.00 +/-0.03mg/mL compared to an NIST reference
- Convenient – choose 1mL ampules, a 50mL bottle, or a complete set containing seven ready-to-use dilutions
- Protein assay quantitation standard (BCA Protein Assay, Coomassie-Bradford Assay, etc.)
- Protein recovery control for desalting and other column procedures
- General calibration of spectrophotometer UV-lamp (absorbance at 280nm)
Selection of a protein standard is potentially the greatest source of error in any protein assay. The best choice for a standard is a purified, known concentration of the most abundant protein contained in the samples being tested. Often, a highly purified, known concentration of the protein of interest is not available or it is too expensive to use as the standard, or the sample itself is a mixture of many proteins (e.g., cell lysate). In such cases, the best standard is one that will produce a normal (i.e., average) color response curve with the selected protein assay method and is readily available to any researcher. BSA is such a protein, and the Pierce Albumin Standards are the most convenient source of ready-to-use BSA standard.
For greatest accuracy in estimating total protein concentration in unknown samples, it is essential to include a standard curve each time the assay is performed. This is particularly true for the protein assay methods that produce non-linear standard curves. Deciding on the number of standards and replicates used to define the standard curve depends upon the degree of non-linearity in the standard curve and the degree of accuracy required. In general, fewer points are needed to construct a standard curve if the color response is linear. Typically, standard curves are constructed using at least two replicates for each point on the curve.
Tech Tip #57: How to use a protein assay standard curve
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Review of Protein Assay Methods
Bovine Gamma Globulin (BGG) Standards (best for coomassie-Bradford assays and antibody samples)
BCA Protein Assay Kit
Pierce 660 nm Protein Assay Kit
All Pierce Protein Assay Kits and Reagents