Unit

UNIT 5.3 Determination of Molecular Size by Zonal Sedimentation Analysis on Sucrose Density Gradients

  1. Michael S. Marks

Published Online: 1 MAY 2001

DOI: 10.1002/0471143030.cb0503s00

Current Protocols in Cell Biology

Current Protocols in Cell Biology

How to Cite

Marks, M. S. 2001. Determination of Molecular Size by Zonal Sedimentation Analysis on Sucrose Density Gradients. Current Protocols in Cell Biology. 00:5.3:5.3.1–5.3.33.

Author Information

  1. University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania

Publication History

  1. Published Online: 1 MAY 2001
  2. Published Print: OCT 1998

Abstract

The molecular weight of a protein is a basic characteristic that can only be approximated by techniques such as gel filtration and electrophoresis. Zonal sedimentation analysis on sucrose gradients is a method for estimating the molecular mass of proteins and protein complexes under nondenaturing conditions. This unit includes protocols for preparing the appropriate gradients, for fractionation and separation of cell lysates on the gradients, for fractionation of the gradients themselves, and use of the results to calculate the molecular mass based on sedimentation coefficient and other parameters. There is also an additional protocol for differential sedimentation on gradients made with water and deuterium oxide to allow for direct determination of the partial specific volume of a protein or complexes.