Electrophoretic analysis, specifically Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis SDS-PAGE , is a widely used technique to determine the molecular weight and purity of protein samples in a given solution. The method separates proteins based on their molecular weight, allowing for the estimation of protein size and assessment of sample purity. Here's how it works:1. Sample preparation: First, the protein sample is mixed with a loading buffer containing SDS sodium dodecyl sulfate , a detergent that denatures the proteins and imparts a uniform negative charge to them. The sample is then heated to ensure complete denaturation and reduction of disulfide bonds. This ensures that the proteins' mobility in the gel will be based solely on their molecular weight and not on their shape or charge.2. Gel preparation: A polyacrylamide gel is prepared with a specific percentage of acrylamide, which determines the pore size of the gel. The percentage is chosen based on the expected molecular weight range of the proteins to be analyzed. A stacking gel with a lower acrylamide percentage is also prepared to concentrate the protein samples before entering the resolving gel.3. Loading and running the gel: The protein samples, along with a molecular weight marker a mixture of proteins with known molecular weights , are loaded into the wells of the gel. An electric field is applied across the gel, causing the negatively charged proteins to migrate towards the positive electrode. The proteins separate based on their molecular weight, with smaller proteins moving faster through the gel matrix than larger ones.4. Staining and visualization: After electrophoresis, the gel is stained with a protein-specific dye, such as Coomassie Blue or Silver Stain, to visualize the separated protein bands. The molecular weight marker is used as a reference to estimate the molecular weight of the protein bands in the sample.5. Analysis: The molecular weight of the protein of interest can be estimated by comparing its migration distance to that of the molecular weight marker proteins. The purity of the protein sample can be assessed by examining the number and intensity of the bands in the sample lane. A pure protein sample will show a single, intense band, while an impure sample will have multiple bands or smeared bands.In summary, electrophoretic analysis, specifically SDS-PAGE, can be used to determine the molecular weight and purity of a protein sample in a given solution by separating proteins based on their molecular weight, staining the separated proteins, and comparing their migration distances to a molecular weight marker.