Page 210 - Color Atlas of Biochemistry

Basics 201

A. Principles of centrifugation

Centrifuge
bucket Mitochondria
1.2
Microsomes

Soluble Nuclei
1.4 proteins Viruses
r eff

Fixed angle rotor Density (g · cm -3) 1.6 Glycogen

Swing-out DNA
centrifuge
bucket Ribosomes, Polysomes
1.8

RNA
2.0

Axis of rotation 2 3 4 5 6 7
1 10 10 10 10 10 10 10
Swing-out bucket rotor Sedimentation coefficient (Svedberg, S)

2
g: Gravitational acceleration g = ω · r eff s: Sedimentation coefficient
(S = 10 –13 s)
v: Sedimentation velocity M: Molecular mass
–1
(cm · s ) 2
v = ω · r eff · s v : Partial specific particle volume
3
–1
(cm · g )
ω: Angular velocity
–1
(rad · s ) r : Density of the solution
M · (1 - v · r) (g · cm )
3
s =
r : Effective radius (cm) f f : Coefficient of friction
eff
B. Density gradient centrifugation
Particles migrate Particles distributed
Probe according to S-value according to density
Centrifugation Centrifugation

Sucrose CsCl
density density
gradient gradient

After t = 0 0.5 1 2 h 0 2 4 8 h

Zonal centrifugation Isopyknic centrifugation

Sucrose or
CsCl gradient
Concentration

1 2 3 4 5 6 7 8 9 10 11 0 1 2 3 4 5 6 7 8 9
Fraction Fraction

Fractionation Detection

Koolman, Color Atlas of Biochemistry, 2nd edition © 2005 Thieme
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