Which buffer is commonly used during the lysis step to extract GFP from cells?

The lysis step in the extraction of green fluorescent protein (GFP) from cells is crucial for breaking down cell membranes and releasing the protein into solution. The use of a buffer that maintains an appropriate pH is key for preserving the stability and functionality of GFP during this process.

Tris-HCl or phosphate-buffered saline (PBS) is commonly employed in this context because these buffers provide a stable environment that mimics physiological conditions, necessary for proper protein solubility and activity. Furthermore, the inclusion of protease inhibitors is vital, as they help to prevent the degradation of GFP by endogenous proteases released during cell lysis. This combination ensures a higher yield and purity of the GFP extracted from the cells.

Other buffers, while they may have specific applications, do not adequately provide the stable conditions required for effective protein extraction and protection. For example, acetate buffers may not provide the ideal pH range for GFP stability, and buffers like citric acid may lead to issues with protein solubility. Thus, the choice of Tris-HCl or PBS with protease inhibitors is standard practice in GFP purification protocols.