The purpose of this experiment is to learn about the principles of protein assays as well as to learn how to utilize the Beer-Lambert Law by doing various calculations such as how to calculate absorbencies, concentrations, and extinction coefficients. According to the Beer Lambert Law, absorbance is proportional to path length and concentration. For this experiment we will be learning how to use a spectrophotometer which measures transmitted light intensity. Spectrophotometers measure wavelength based on the color produced. In addition, we will be using standard curves to calculate protein concentrations. This experiment is extremely beneficial to biochemists because determining the amount of protein in a solution is crucial. Also, because spectrophotometers are useful for determining the substances that …show more content…
It is clear that each method will provide different advantages and disadvantages being that there are protein assays that are dye binding and those that are based on alkaline copper (lab manual). The first will be the Absorbance at 280 nm which is a quick method that is used to find protein peaks. Proteins that contain tyrosine, phenylalanine, and tryptophan have a strong absorbance for UV light at 280 nm. According to the Material Safety Data Sheet, tyrosine can be slightly hazardous in the case of skin contact. In addition, phenylalanine can be hazardous if it comes into contact with eyes, if it is ingested, or if it is inhaled. Additionally, tryptophan may cause skin or eye irritation. Equipment used in this method include the spectrophotometer, quartz cuvette, and disposable pasteur pipette. To begin this method we set the spectrophotometer to 280 nm and allow it to warm up for a period of 30 minutes. Then we set it to zero with a buffer. We then remove the blank buffer, add a protein sample, and then read the absorbance (lab