25 May 2011

Size Exclusion Chromatography (SEC)




Introduction

Size-exculsion chromatography (SEC), furthermore called gel-filtration or gel-permeation chromatography (GPC), uses porous particles to separate molecules of uncommon sizes. It is commonly used to separate biological molecules, and to determine molecular weights and molecular consequence distributions of polymers. Molecules with the intention of are less important than the stoma size can enter the particles and therefore be inflicted with a longer path and longer transist calculate than better molecules with the intention of cannot enter the particles.
Schematic of a size-exclusion chromatography column

Molecules better than the stoma size can not enter the pores and elute collectively as the initially summit in the chromatogram. This condition is called whole exclusion. Molecules with the intention of can enter the pores will be inflicted with an mean residence calculate in the particles with the intention of depends on the molecules size and affect. Different molecules therefore be inflicted with uncommon whole transit era through the column. This portion of a chromatogram is called the selective permeation region. Molecules with the intention of are less important than the stoma size can enter all pores, and be inflicted with the highest residence calculate on the column and elute collectively as the continue summit in the chromatogram. This continue summit in the chromatogram determines the whole permeation limit.




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