How to use CTAB?

Fernando Sesma cerela at
Thu Jun 12 16:06:14 EST 1997

Here is the protocol from Ausubel et al. (Short protocols in Molecular
Biology, 2nd Ed)
for Removal of polysaccharides from existing DNA genomic preps. (from
Murray, M.G. and Thompson, W.F. 1980. Rapid isolation of
high-molecular-weight plant DNA. Nucl. Acid Res.8:4321-4325).

1. Adjust NaCl concentration to 0.7 M and 0.1 vol. CTAB/NaCl solution 

(Dissolve 4.1 g NaCl in 80 ml H2O and slowly add 10 g CTAB
(Hexadecyltrimethyl ammonium Bromide, Sigma catalog Nr H6269), while
heating and stirring.
 If necessary, heat to 65 degrees C to dissolve. Adjust final volume to 100

2. Extract with chloroform/isoamyl alcohol (24:1). 
   (A white interface indicates removal of polysaccharides and other
contaminating    macromolecule).

3. Repeat CTAB extraction and Chloroform/isoamyl alcohol extraction until
no interface is visible.

If you need the complete genomic DNA isolation protocol, please e-mail me.




Dr. Fernando Sesma
Tucumán - Argentina
cerela at
Fax/Phone 54-81-310465 /311720

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