What is the composition of the Elution Buffer (TE)?

The correct answer is characterized as a very low salt buffer. The elution buffer, specifically when used in the context of purification processes like affinity chromatography for proteins such as Green Fluorescent Protein (GFP), typically has a composition designed to gently release the bound protein from the column without causing denaturation or precipitation.

Low salt concentrations help to maintain the solubility of proteins while allowing for the elution of the desired target. Proteins are often bound in high-salt conditions to ensure strong interactions with the resin; elution with a low salt buffer effectively disrupts these interactions without overwhelming the protein's stability. This helps to maximize yield while maintaining the integrity of the purified protein, which is essential for any subsequent analyses or applications of GFP.

In contrast, a very high salt buffer would likely lead to issues with protein solubility and could precipitate proteins, while a concentrated enzyme solution would not be relevant for the purpose of elution in this context. Buffered salt solutions can vary in their ionic strength and may not specifically convey the idea of low salt, which is the key characteristic of the elution buffer used in this scenario.