“Aspirating the supernatant” is a term used in laboratory protocols and refers to the process of removing the liquid portion (supernatant) that lies above a pellet of cells or other solid material in a tube or flask after centrifugation or sedimentation.
Here’s a general outline of the process:
- Following centrifugation, the tube will have two layers: the cell pellet (solid material) at the bottom and the supernatant (liquid portion) at the top.
- To aspirate the supernatant, a pipette, a syringe, or an automated device is used.
- The tip of the pipette is carefully lowered into the tube, taking care not to disturb the pellet.
- The supernatant is gently drawn off into the pipette and discarded or collected for further analysis, depending on the protocol.
Aspirating the supernatant is a common step in many laboratory procedures including cell culture, DNA/RNA extraction, and protein purification. It’s used to remove unwanted media, reagents, or cellular debris, leaving behind only the cells or substances of interest.
Aspiration should be done slowly and carefully to prevent disturbing the cell pellet and to ensure that none of the desired material is accidentally removed. In some cases, a small amount of supernatant is deliberately left behind to prevent loss of the pellet.