The Bradford Assay is a form of colorimetric and spectroscopic analysis developed to determine the concentration of a protein; in an aqueous solution. Produced by Marion Bradford in 1976, it was an innovation of its time due to various factors including its simplicity, rapid results, reproducibility and high sensitivity of 0 to 0.01 mg (Martina and Vojtech, 2015); compared to other tests such as the Lowry and Biuret method, with which he was successful. Say no to plagiarism. Get a tailor-made essay on “Why Violent Video Games Should Not Be Banned”? Get the original essay The Bradford Reagent is composed of a mixture of Coomassie Brilliant Blue G-250 dye dissolved in a mixture of phosphoric acid and methanol. The test is based on an absorbance shift of the Coomassie Brilliant Blue G-250 dye in which, under acidic conditions, the red form of the dye is converted to its blue form when it binds to the protein being analyzed. The bond between the dye and the protein occurs as a result of interactions between the basic amino acid residues on the proteins and the free electron pair of the dye. This causes the native form of the protein to be distorted and some of its hydrophobic residues exposed. These hydrophobic residues bind to nonpolar regions of the dye, resulting in van der Waals forces. Additionally, these Van der Waals forces lead to the positioning of the positive amine groups closer to the negative charge of the dye, which allows the protein-dye complex to be strengthened by ionic bonding. This results in a color of the dye ranging from red to blue, which we can best detect at a light wavelength of 595 nm. Overall, this shows that the instability of Coomassie Brilliant Blue G-250 dye is stabilized by protein binding. Therefore, as protein content increases, more protein-dye complexes form and more staining occurs, which may be the case; thus, the amount of complex present in the solution is a measure of protein concentration and can be estimated using an absorbance reading. As there is a direct relationship between the absorbance of a solution and the concentration of soluble proteins. This is known from the Beer-Lambert law, which states that the concentration of a solute is proportional to the absorbance. Keep in mind: this is just a sample. Get a personalized paper now from our expert writers. Get a Custom Assay The objectives of the experiment were to: Create a dilution series of protein standard with bovine serum albumin (BSA) and perform the Bradford protein assay on these known protein concentrations. Use the previous concentrations to create a calibration graph measured against absorbance and use this graph to find the protein concentration in two cell extract samples. Overall, the experiment was conducted to determine the protein concentration in two cell extracts of unknown protein concentration using the Bradford protein assay..