Question

Pure fraction of cellular components can be isolated by

• A. Chromatography
• B. Scanning electron microscopy
• C. X-ray diffraction
• D. Differential centrifugation
• E. Autoradiography

Answer 1

The correct option is D Differential centrifugation

Cell fractionation is the technique of separating and rupturing cells, and separating their components for study. It has two steps: homogenisation (rupturing of cells) and differential centrifugation.
Differential centrifugation is separation of different components of homogenate (supernatant obtained after homogenization) by subjecting it to successively higher centrifugal force that brings about velocity sedimentation. Denser constituents undergo sedimentation at lower centrifugal force while lighter fractions settle down at higher centrifugal force.

The various fractions separated during differential centrifugation are nuclear fraction, mitochondrial fraction, microsomal fraction and free ribosomal fraction.