How to get a single stranded DNA as long as 2-3kb?

[ChenHA]

On Mon, 11 Jun 2007 16:22:57 -0400, Nick Theodorakis
<nick_theodorakis from hotmail.com> wrote:

>ChenHA wrote:
>[...]
>> 
>> Perhaps I misremember, was it XL1 blue cells that produces the ghost
>> band of ssDNA instead?   
>> 
>> 
>
>I seem to remember a discussion about NaOH irreversibly altering the 
>plasmid conformation to generate a ghost band during alkaline preps, but 
>perhaps there is more than one kind of ghost band.
>

You get the denatured DNA  whatever cells you use.  There is a
specific ghost band that you get with XL1Blue cells IIRC, it appears
much smaller than the supercoiled plasmid itself (I think the
denatured DNA always runs bigger), and an ex-colleague always gets
them (he used XL1Blue, I don't, and I never see this band).   I think
someone once tried to excise the band, retransformed into cells, and
got the plasmid back, so it was thought to be ssDNA, but no one seems
to be sure about it.  

Just wondering, might be useful for the original poster if it is
indeed ssDNA.  

>Nick