How is GFP often visualized during purification?

The visualization of green fluorescent protein (GFP) during purification is predominantly achieved through fluorescence imaging under UV light. This is because GFP has a unique property that allows it to emit green fluorescence when exposed to ultraviolet radiation. This characteristic makes it an excellent marker for tracking and analyzing the presence and purity of GFP during purification processes.

The typical methodology involves exposing the purified sample or the cells expressing GFP to UV light, which causes the protein to fluoresce brightly. This fluorescence can be detected and quantified, allowing researchers to confirm the presence of GFP and gauge the effectiveness of the purification process. The ability to visualize GFP in real-time provides significant advantages in monitoring purification steps and verifying that the protein has not been degraded or lost.

Other methods, such as colorimetric assays or high-performance liquid chromatography (HPLC), are used in different contexts but do not exploit the unique fluorescent properties of GFP for visualization. Assessing cell growth rates is primarily related to measuring cellular health or productivity rather than directly visualizing a specific protein like GFP.