What is the primary reason for discarding the supernatant during the GFP purification process?

The choice indicating that the supernatant contains bacterial growth media is indeed aligned with the purification process of GFP. During the initial steps of this process, when cells are lysed to release their contents, the resulting mixture includes not only the target protein (GFP) but also various other components from the cell, including residual bacterial growth media, cellular debris, and other proteins.

Disposing of the supernatant is essential because it helps to eliminate these unwanted materials while preserving the desired GFP, which is typically found in the pellet after centrifugation. This step is crucial in the purification workflow as it ensures that the subsequent purification steps are focused on isolating and concentrating the GFP rather than dealing with a mixture that would complicate and reduce the overall purity and yield of the target protein.

This understanding underscores the importance of properly segregating the components during protein purification, focusing on obtaining the cleanest possible extract that is rich in the target protein without the interference of extraneous materials. The presence of bacterial growth media in the supernatant makes this material unsuitable for further processing aimed at purifying the GFP, thereby justifying its discard in the purification process.