Bradford Protein Case Essay Example for Free

Bradford Protein Case EssayThe appearance of blue color showed the gift of protein in the BSA dilutions. The much diluted the solution was, the less blue it was. The R2 value of the measuring rod curve of BSA dilution was obtained to be 0.9972, which is close to 1. The closer to 1 the R2 value was, the more accurate the linear portion was.The mistake percentage of individually unknown was large 25.9% for skim milk, 95% for soy sauce, and 64.7% for egg white. The vast difference between the theoretical protein concentration and experimental protein concentration of the unknowns showed that Bradford Protein Assay must have limitations. The Coomassie dye only interacts with certain amino acids such as arginine, histidine, lysine, tyrosine, tryptophan and phenylalanine. However, each amino acid has different structure from each other thitherfore the Coomassie dye will interact differently with each amino acid. The Coomassie dye molecules are bound to proteins by elctronstati c attraction enhanced by hydrophobic bonding (Tal et al. 1984). Besides the interaction between Coomassie dye and amino acids, some compounds mountain arbitrate the result of the Bradford assay such as salt, fat, and detergent. Another factor that could influence on the Bradford assay is the protein sample must fall within the linear swear of standard curve.Another possible explanation for the difference between theoretical protein concentration and experimental protein concentration is human factor. The bottom part of the cuvettes was not vatic to be touched by because that was a region in which the beam of light goes through. The absorbance values at 595 nm are part of the variable of the standard formula that was used to calculate the experimental protein concentration of the unknowns. Therefore, the adjustments in these absorbance values would effectively affect on the experiment protein concentration values. Pipetting could be another error source because it was difficult t o pipette exactly 20 l Coomassie dye. Moreover, as recording the absorbance by using the spectrophotometer, different results were obtained within one sample. That means there were certain minor factors that influenced on the instrument.Bradford protein assay was used to determine protein concentration in several samples. Moreover, Bradford protein assay was not able to detect the presence of melamine in the food because the experimental protein concentration was obtained to be -0.005 mg/ml, which is invalid. Bradford protein assay didnt interact with melamine even though it contains so many amino groups (Field and Field 2010). Melamine is not protein because it doesnt have either carboxyl groups or functional groups, which are components of an amino acid. At high level, melamine can be toxic by combining with cyanuric acid to form insoluble crystals, which lead to the formation of kidney stones (Eufic, n.d.). Melamine amounts make the amount of protein look higher than they real are when tests that are used to detect nitrogen are used (Science Daily, 2009). Even though melamine has been notified to be toxic, there are still song of melamine-contaminated food in the market because the melamine tests are way to expensive to apply on every single product and take to much sequence to proceed.In future, to test the accuracy of the Bradford protein assay, more trials will be conducted with different proteins such as protein shake, chicken broth and 2% whole milk. Since the disability of sensing of the Bradford protein assay, some other methods should be conducted to see whether they could detect the presence of melamine in the food. The University of Minnesotas BioTechnology Institute developed an enzyme that is used in Bio Scientifics new MaxDiscoveryTM Melamine Test kit, which simplifies the detection of melamine contamination in food (World Health Organization, n.d.). The melamine deaminase enzyme is created to break one of the C-N bonds in melamine to rele ase ammonia.Clearly, the Bradford Protein Assay still has some limitations to detect melamine in the food. Therefore, to provide safety food, a better and inexpensive protein method inevitably to be created.Reference1. Anjarie F., Jeffrey F. Melamine and cyanuric acid do not interfere with Bradford and Nyhydrin assays for protein determination. Food Chemistry 121(2010) 912917 2. Mosche T., Aaron S., Elizabeth N. 1984. Why does Coomassie Brilliant Blue R interact differently with different proteins?. Journal of Biological Chemistry 260(18) 9976-9980 3. European Food Information Council (EUFIC). N.D. Frequently Asked Questions. http//www.eufic.org/page/en/page/faq/faqid/what-is-melamine/ Accessed February 22, 2013. 4. Science Daily. 2009. Simple, Inexpensive Method to watch Melamine Poison in Food. Last updated July 22, 2009. http//www.who.int/csr/media/faq/QAmelamine/en/index.html. Accessed February 22, 2013. 5. World Health Organization. N.D. Global Alert and Response (GAR). http //www.who.int/csr/media/faq/QAmelamine/en/index.html . Accessed February 22, 2013.