Question

Platelets are extracted from plasma by the process

• A. Autoclave
• B. Filtration
• C. Dialysis
• D. Centrifuge

Hint:

Centrifugation is a key method for separating components of blood, such as platelets, based on their density.

Answer 1

The Correct Option is D

Platelets are denser than the surrounding plasma, so spinning whole blood or plasma in a centrifuge causes the platelets to settle into a pellet while the less dense plasma remains as the supernatant above. This density-based separation is the standard method for isolating platelets, distinct from autoclaving (sterilization), filtration (size-based separation), and dialysis (small-molecule diffusion across a membrane).

Therefore, the correct answer is Centrifuge.

Answer 2

Another way to confirm this is to think about what physical principle each technique relies on, and match it to how platelets differ from plasma.

1. Autoclave: This technique relies on heat and pressure for sterilization, a principle with no relevance to separating intact cellular components from a fluid.
2. Filtration: This relies on straining particles through pores of a defined size, which is not precise enough to reliably separate platelets from plasma proteins and other components.
3. Dialysis: This relies on the diffusion of small solutes across a semipermeable membrane, a principle suited to removing small molecules, not isolating cellular elements like platelets.
4. Centrifuge: This relies on centrifugal force acting on components of different densities, causing platelets to pellet out from the less dense plasma, which is exactly the property exploited to isolate platelets.

Matching each method's underlying principle to the density difference between platelets and plasma points to centrifugation.

Therefore, the correct answer is Centrifuge.