epitope tag: two or one?

[Chris Boyd]

Frank O. Fackelmayer (fof1 at chclu.chemie.uni-konstanz.de) wrote:
: Chris Boyd wrote:
: > 

<snip -- use of 132 nt long oligos for epitope tagging>

: > They're still usable for PCR though, as many published papers testify.

: Yes, they can be used for PCR, but that does not say they have the correct
: sequence. Have some 10 correct bases at the 3´ end, and viola, your PCR will
: work.

Thanks for that, but I had already grasped the principle of PCR.

Nowhere have I claimed that when you order a batch of 132-mers they are
all of the correct sequence, and I fully realise such long syntheses
are pushing the current technology to the limit.  I was offering an
extreme example to illustrate a point -- in reality, it would be safer
to add no more than two or three tags by a single PCR.

However, unless you or someone else can convince me otherwise by
reference to published data, I will still cherish the notion that a
usable fraction of a 132-mers batch (if HPLC-purified) has a sufficient
proportion of oligos of correct sequence to make their use as I've
outlined a viable option.

Best wishes,
-- 
Chris Boyd                      | from, but not \ MRC Human Genetics Unit,
Christopher.Boyd at hgu.mrc.ac.uk  | on behalf of  /  Western General Hospital,
http://www.hgu.mrc.ac.uk/Users/Christopher.Boyd \   Edinburgh, EH4 2XU, SCOTLAND