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

The correct answer is Centrifugation

Explanation:

• Centrifugation is a technique that involves the use of centrifugal force to separate components of a mixture based on their density.
• It is widely used in laboratories for the analysis of blood samples, among other applications.
• In blood tests, centrifugation helps to separate blood cells from plasma or serum, which is essential for various diagnostic tests.
• The rate of separation in a suspension of particles by way of gravitational force mainly depends on the particle size and density.
• Particles of higher density or larger size typically travel at a faster rate and at some point will be separated from particles less dense or smaller.
• In blood tests, centrifugation is employed to separate the different components of blood, such as plasma, red blood cells (erythrocytes), white blood cells (leukocytes), and platelets.

Other Options:

• Filtration: This technique is used to separate solids from liquids or gases using a filter medium that allows only the fluid to pass through. It is not suitable for separating components of blood.
• Chromatography: This method is used to separate and analyze components of a mixture based on their movement through a stationary phase. While useful for many applications, it is not typically used for routine blood tests in diagnostic laboratories.
• Crystallization: This process involves the formation of solid crystals from a homogeneous solution. It is generally used in chemical processes for purifying substances and not for blood analysis.