What is the most common method used for GFP purification?

Affinity chromatography is the most commonly used method for the purification of Green Fluorescent Protein (GFP) due to its high specificity and effectiveness in isolating target proteins. This technique is based on the specific interaction between the GFP and a ligand that is attached to a stationary phase, often utilizing a representation of the histidine tag that is frequently engineered into the GFP construct.

When a mixture containing GFP is passed through a column with this stationary phase, GFP binds strongly to the ligand, allowing for other proteins, which do not have the specific binding affinity, to be washed away. Subsequently, GFP can be eluted from the column under conditions that disrupt this interaction, resulting in a highly purified form of the protein.

The high purity and yield often achievable with affinity chromatography, along with its capacity to work well under a variety of conditions and scalability for larger quantities, make it the preferred choice when purifying GFP in laboratory settings. Additionally, the intrinsic properties of GFP, such as its fluorescent characteristics, provide a straightforward means to monitor the purification process visually, enhancing its utility even further.