Blood fractionation

Blood fractionation is the process of fractionating whole blood, or separating it into its component parts. This is typically done by centrifuging the blood.

The resulting components are:

a clear solution of blood plasma in the upper phase (which can be separated into its own fractions, see Blood plasma fractionation),
the buffy coat, which is a thin layer of leukocytes (white blood cells) mixed with platelets in the middle, and
erythrocytes (red blood cells) at the bottom of the centrifuge tube.

Serum separation tubes (SSTs) are tubes used in phlebotomy containing a silicone gel; when centrifuged the silicone gel forms a layer on top of the buffy coat, allowing the blood serum to be removed more effectively for testing and related purposes.

As an alternative to energy-consuming centrifugation, more energy-efficient technologies have been studied, such as ultrasonic fractionation.^[1]

^ Smalberger C, Nathan M, Rubin DM, Nel M, Kotopoulis S, Carlson CS, Postema M (2022). "Experimental setup for the ultrasonic fractionation of flowing whole blood in a capillary". Current Directions in Biomedical Engineering. 8 (2): 89–92. doi:10.1515/cdbme-2022-1024.

[1] Smalberger C, Nathan M, Rubin DM, Nel M, Kotopoulis S, Carlson CS, Postema M (2022). "Experimental setup for the ultrasonic fractionation of flowing whole blood in a capillary". Current Directions in Biomedical Engineering. 8 (2): 89–92. doi:10.1515/cdbme-2022-1024.

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