A pre-stained molecular weight marker comprised of two sets of proteins, each labeled with a distinct chromophore, is used in protein electrophoresis. This marker allows researchers to visualize the migration of proteins during electrophoresis and estimate their sizes by comparing them to the known sizes of the stained proteins. A common example features one set of proteins stained blue and another stained red, enabling clear differentiation and improved size estimation accuracy across a wider molecular weight range.
These markers offer significant advantages over single-color markers, particularly for analyzing complex protein mixtures. The distinct colors aid in visualizing protein separation across the gel, allowing for more accurate size determination, particularly in higher and lower molecular weight regions where single-color ladders might be less clear. Furthermore, the presence of two sets of differently colored proteins increases the number of reference points for molecular weight estimations, enhancing precision. This technology has become an essential tool in modern biological research for various applications, from confirming the success of protein purification steps to characterizing the components of complex samples.