Final answer:
Laemmli Buffer is used to prepare protein samples for SDS-PAGE by denaturing the proteins and giving them a uniform negative charge, enabling their separation by size during electrophoresis.
Step-by-step explanation:
The purpose of Laemmli Buffer (Sample Buffer) is to prepare protein samples for SDS-PAGE. When performing SDS-PAGE, also known as sodium dodecyl sulfate-polyacrylamide gel electrophoresis, proteins must be prepared in a way that they can be properly separated based on their size during the electrophoresis process. Laemmli Buffer contains chemicals like SDS, a detergent that denatures proteins and masks their inherent charges, making them uniformly negatively charged. This process allows proteins to be separated irrespective of their original charges when an electric current is applied during SDS-PAGE.
It is worth noting that the Laemmli Buffer is not used for staining proteins in the gel, which is often done with Coomassie Brilliant Blue or silver stain, nor is it used to visualize protein bands in the gel. Also, it is not involved in the process of transferring proteins from the gel to a membrane, which is a step in the immunoblotting technique known as western blotting.