Prestained protein ladders for approximate sizing of proteins and great protein PAAG electrophoresis results

The difference between prestained and unstained protein ladder or marker

A protein ladder is a mixture of stained proteins of a known molecular weight that are visible without gel staining. The chromophores that provide the colour to the proteins change the migration of the native proteins, therefore, the prestained protein ladders are used only for an approximate molecular mass estimation of test proteins on denaturing polyacrylamide electrophoresis gels and for monitoring of the protein transfer efficiency on membranes in Western blotting experiments.

High quality prestained protein ladders such as highQu Cozy™ Prestained Protein Ladder are excellent for fast and convenient protein electrophoresis experiments whereas, the below discussed unstained protein markers are the tools of choice for a precise estimation of molecular weight of the target proteins.

A protein marker is normally a mixture of unstained well-known proteins of a well-known molecular mass. The proteins of the marker are not visible on the gel without staining (for example Coomassie blue or silver staining), and their migration pattern is precisely known. Unstained protein markers are preferred when the precise protein molecular mass estimation is important.