Liquid Cultures
Liquid cultures are used when you want to isolate a gene or protein from a media. Liquid cultures can also be a way to grow up bacteria. It usually occurs after centrifugation. The liquid on the top of the tube is called the supernatant. This liquid material is called the liquid culture. This liquid can be ran through a series of HIC tubes in order to isolate the gene/protein that is being studied. Liquid cultures may also be used because they are easier to aerate than solid media.
The liquid in the tube is the supernatant and the stuff at the bottom is the protein.