Centrifugation
Centrifugation separates solutions/molecules/particles/etc on the basis of size and density. Heavy things go down, light things go up. Centrifugation was extremely important throughout the entire process of pGLO transformation, GFP Purification, and Protein Characterization. It was used intermittently throughout all protocols to separate out the desired materials or to make sure everything in the tube ended up at the bottom, and therefore in the sample mixtures. If the solid is what you are after, the supernatant (top layer of liquid) may be decanted or pipetted out of the tube. If the supernatant is needed, it can be poured into another tube. The remaining pellet (solid) may then be discarded. However, it is highly recommended that you keep all materials, whether they are deemed "needed" or "discard" to avoid mix-ups and the potential for required repetition.