Posted 30 March 2005 - 01:22 PM
Posted 04 December 2009 - 05:24 PM
I've had problems with some site-directed mutagenesis (following Strategene's Quikchange II protocols) and tried using the Quikchange II XL kit that is basically the same outside the inclusion of "QuikSolution" reagent. I noticed a marked increase in mutant generation (i.e. from 0 colonies to over 100) with high efficiency (~100%). Does anyone know the contents of this magical reagent? Strategene is tight-lipped about the proprietary reagent and only offered that too much of it will reduce the fidelity of the polymerase. Is it Mg2+ based? Or something else . . . ?
I found a post on the Methods mailing list
That says that the reagent is DMSO. I talked to tech support at Stratagene and they told me that the purpose of the QuikSolution was to help dissociate GC-rich regions so the polymerase can continue to make new DNA. In addition to your info about too much of it inhibiting the reaction, this totally jives with the effects of DMSO on PCR.