"How is protein gel electrophoresis useful? It's like making spaghetti- when you finish boiling the noodles, you strain the noodles away from the water. The noodles don't do through the holes in the strainer because they're too big. If they were smaller, the noodles could fit through the holes. Proteins are like different sized noodles and the agarose gel is like a strainer, filled with little holes. Proteins that are small moves easily through the holes in the agarose gel, while larger proteins move more slowly, getting stuck in the holes in the gel. Thus, protein gel electrophoresis allows students to spread out the proteins from different bovine tissues, creating a protein fingerprint that serves as a barcode to identify that type of cell or tissue. "