Which one among the following separation techniques is used for blood tests in diagnostic laboratories ?

Centrifugation is the standard separation technique used in diagnostic laboratories for blood analysis. It operates on the principle of sedimentation under centrifugal force.

• Mechanism: When a blood sample is spun at high speeds in a centrifuge, the components separate based on their density. The denser particles, such as red blood cells and white blood cells, are pushed to the bottom of the test tube.
• Result: The lighter component, the plasma (or serum), remains in the upper layer. This separation allows technicians to perform specific tests on either the cells or the liquid portion of the blood.

In contrast, Filtration is not used as it can damage blood cells; Chromatography is used for identifying chemical constituents in complex mixtures; and Crystallization is a purification technique for solids, making them unsuitable for primary blood component separation.