Proteomics/Protein Separations - Centrifugation/Preparative Centrifugation vs. Analytical Centrifugation

Table of Contents: Protein Separations - Centrifugation
 * 1) History of the Centrifuge
 * 2) How the Centrifuge Works
 * 3) Density Gradient Centrifugation
 * 4) Differential Centrifugation
 * 5) Preparative Centrifugation vs. Analytical Centrifugation

Analytical
·     Uses small sample size (less than 1 ml)

·     Built in optical system to analyze progress of molecules during centrifugation

·     Uses relatively pure sample

·     Used to precisely determine sedimentation coefficient and MW of molecules

·     Beckman Model E is an example of centrifuge used for these purposes.

Preparative
·     Larger sample size can be used

·     No optical read-out – collect fractions and analyze them after the run

·     Less pure sample can be used

·     Can be used to estimate sedimentation coefficient and MW

·     Generally used to separate organelles and molecules. Most centrifugation work done using preparative ultracentrifuge

·     Several models available, including L5-65 and L5-75 used for preparative purposes.