In the context of GFP purification, what does the term 'elution' refer to?

In the context of GFP purification, 'elution' specifically refers to the release of bound protein from a chromatography column. This process is essential in protein purification, where proteins are separated based on their interactions with the stationary phase of the column. During elution, a specific buffer, often with a different concentration of salt or a competing molecule, is used to disrupt these interactions and allow the target protein—in this case, GFP—to be released from the column. This step is critical for isolating the desired protein after it has been selectively retained during earlier stages of the purification procedure.

Understanding this concept is pivotal, as effective elution ensures that the maximum amount of the protein of interest is recovered for further analysis or use. This process can include adjusting the pH or ionic strength of the buffer to optimize recovery based on the properties of the bound protein.