Lecture 3 - Density Gradient Centrifugation

Question 1

What is density Gradient Centrifugation

Answer 1

Density Gradient Centrifugation is the preferred method to purify subcellular organelles & macromolecules.

Question 2

What happens in Density gradient centrifugation?

Answer 2

Density gradients can be generated by placing layers of gradient media such as sucrose in a tube with the heaviest layer at the bottom & lightest at the top followed by centrifugation.

Question 3

What are the two categories of density gradient?

Answer 3

1) Rate zonal (size) separation
(2) Isopycnic (density) separation

Question 4

Void Volume (Vo)

Answer 4

Volume in interstitial space between gel beads

Question 5

Inner Volume (Vi)

Answer 5

Partial volume of liquid in gel phase
 Vi = p.r2h – Vo
 Vi = Vt - Vo

Question 6

Elution Volume (Ve)

Answer 6

is the volume required to elute a particular compound from the column

Question 7

Kav (Partition coefficient)

Answer 7

Indicates the fraction of inner volume accessible to a particular compound.