Molecular markers
DNA purification
Silica adsorption

Topic Completed: 1 April 2012

Revised: 15 February 2019

Copyright: 2008-2018,, Inc.

PubMed Search: Silica adsorption[TIAB]

Rodney E. Shackelford, D.O., Ph.D.
Page views in 2018: 11
Page views in 2019 to date: 40
Table of Contents
Definition / general
Cite this page: Shackelford R. Silica adsorption. website. Accessed September 19th, 2019.
Definition / general
  • Uses a silica microchannel matrix with a specific salt concentration and pH (Wikipedia: DNA Separation by Silica Adsorption [Accessed 29 May 2018])
  • DNA within a previously prepared cell lysate or other crude nucleic acid mixture preferentially binds to the walls of the microchannels in the presence of a high salt buffer
  • DNA binds to the silica under conditions of high ionic strength and a pH at or below the pKa of the silica surface silanol (SiOH) groups
  • Multiple washing steps with an alcohol based wash buffer remove other cellular constituents, particularly proteins
  • Later the pure DNA is removed with a specific low salt elution buffer; presently, this technique is relatively expensive, limiting its application
  • Many automated DNA extraction machines employ a silica matrix for DNA capture and purification
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