During which step of GFP purification is a lysis buffer typically used?

The lysis buffer is crucially used during the cell disruption phase of the GFP purification process. In this phase, cells containing the green fluorescent protein are subjected to conditions that break down their membranes, releasing their contents into the solution. The lysis buffer contains various components, such as detergents, salts, and sometimes enzymes, that facilitate the breakdown of the cell membrane and help to solubilize the target proteins.

Using a lysis buffer is essential for maximizing protein yield, as it ensures that the GFP is extracted effectively from the cellular environment. The buffer also often includes protease inhibitors to prevent the degradation of proteins during this process. This step is foundational for the subsequent purification processes, as it directly influences the quality and quantity of the GFP available for further purification stages.