What is a common method to assess the quality of GFP during purification?

Using fluorescence measurements is an effective method to assess the quality of GFP during purification because the protein’s defining characteristic is its ability to fluoresce. GFP contains a chromophore that, once formed through a series of internal modifications, allows it to emit light upon excitation with specific wavelengths. This fluorescence is directly related to the integrity and functional status of the protein. High fluorescence intensity typically indicates that the GFP is correctly folded and properly expresses, while diminished fluorescence can suggest misfolding or degradation.

In addition to being a measure of purity, fluorescence can also provide information about the concentration of the protein and its functionality, making it a versatile tool in protein analysis. This capability is essential in determining the success of the purification process and in ensuring that the GFP can be used effectively in subsequent applications, such as tagging in cellular studies or as a reporter in gene expression assays.