Understanding Supernatant - The Clear Liquid Left Behind After Separation

Supernatant is the liquid portion of a suspension or emulsion that remains after the solid particles have settled out. In other words, it is the clear liquid that is left over after the sediment or precipitate has been removed.

For example, if you were to mix sand with water and let it sit for a while, the sand particles would settle to the bottom of the container, leaving behind a clear supernatant liquid on top. Similarly, when blood is spun in a centrifuge, the red blood cells and other solid particles will settle to the bottom of the tube, leaving behind a clear supernatant plasma at the top.

Supernatant can also refer to the liquid portion of a cell culture or other biological suspension that has been separated from the solid particles or cells using a centrifuge or other separation technique. In this context, the supernatant may contain nutrients, growth factors, or other substances that are important for the growth and maintenance of the cells.