Why is the pellet discarded during the purification procedure?

The pellet is discarded during the purification procedure primarily because it does not contain GFP, which is the target protein. During the purification process, cells are typically lysed to release their contents, and subsequent centrifugation helps separate the soluble proteins from the insoluble cellular debris, which accumulates as a pellet.

The soluble fraction, where GFP is located, is retained for further purification steps. The pellet often contains cell membranes, inactive proteins, and other unwanted cellular components that are not of interest for GFP purification. Since the goal is to isolate and purify the GFP, the pellet that lacks the target protein is discarded to ensure that only the fractions containing GFP are further processed. This efficient separation process is crucial in obtaining a high-purity yield of GFP for downstream applications or analysis.