Paper chromatography is a separation technique that is commonly used to identify and quantify the different amino acids present in a sample. In this lab report, we will describe the steps involved in performing a paper chromatography experiment to separate and identify the amino acids in a protein sample.
The first step in the paper chromatography experiment is to prepare the sample. This involves dissolving the protein in a suitable solvent, such as water or a buffered solution. The sample is then applied to the chromatography paper, which is placed in a developing chamber filled with a suitable solvent.
As the solvent moves up the paper by capillary action, it also carries the sample compounds with it. The different amino acids in the sample will have different affinities for the solvent and the chromatography paper, and will therefore move at different rates. This results in the separation of the amino acids as they move up the paper.
To visualize the separation, a suitable dye or indicator can be added to the solvent. This will cause the amino acids to appear as distinct bands on the paper as they are separated. The distance that each amino acid travels up the paper can be measured and used to calculate the relative abundance of each amino acid in the sample.
It is important to carefully control the conditions of the experiment, such as the type and concentration of the solvent, the temperature and humidity of the developing chamber, and the type of chromatography paper used. These variables can all affect the separation and identification of the amino acids.
Once the amino acids have been separated, they can be identified using various techniques. One common method is to compare the positions of the bands on the chromatography paper to those of known amino acids that have been run under the same conditions. Another method is to chemically modify the amino acids and rerun them on the chromatography paper to see how their positions change.
In conclusion, paper chromatography is a useful technique for separating and identifying amino acids in a protein sample. By carefully controlling the conditions of the experiment and using various techniques for identification, it is possible to accurately determine the amino acid composition of a protein.
