CTAB vs. SDS in DNA extraction? - (Mar/15/2006 )

does anyone know if there is a difference/benefit when using CTAB (hexadecyltrimethylammonium bromide) or SDS (sodium dodecyl sulfate) with a phenol/chloroform procedure? from what i can find CTAB is a cationic surfactant used commonly in plant extractions, and SDS is anionic, but we don't know which would be better for our purposes.

thanks for any suggestions!
~a
masmith@nature.berkeley.edu

As far as I know you can't substitute CTAB for SDS. You use SDS to disturb cell walls, and CTAB for removal of polyphenolic and other organic molecules like polysacharides. You can substitute CTAB for PVP, but if you work with plants, CTAB is better.
You can make a lysis mix with both SDS and CTAB, and then do phen/chlrf extraction.
Make sure that all reagents are at room temp, since CTAB precipitates at lower temperatures.

I agree with yata.

I've found DTAB to work better than CTAB for extracting genomic DNA and RNA (at least from soybean and maize), so that's another option for you.

_Hank

thanks! that was incredibly helpful.
~a