How to measure Cy5-primer concentration ??
blackhole at abuse.plus.com
Fri Oct 6 03:43:46 EST 2006
Historians believe that in newspost <qbhVg.1176$iP5.1045 at newsfe07.lga>
on Fri, 6 Oct 2006, DK <dk at no.email.thankstospam.net> penned the
following literary masterpiece:
>Sure it does. What is there in Cy5 structure that indoles suddenly would
>stop absorbing ultraviolet? Nothing. Sorry, I don't believe it. Sure, you can
>say that it absorbs at ~ 280 stronger than at ~ 260 and that single Cy5
>contribution to the UV absorbance of the whole oligo is small - and I
>would agree. But to say that it does not absorb at all and that it can
>always be neglected is an overkill.
>WRT the original question, quantifying based on Cy5 absorption is
>definitely more precise approach.
If one goes to IDT's web site and uses their calculator program, then a
random 24mer with Cy5 at the 5' end gives about a 5% change between
OD260 compared to same sequence without Cy5.
So yes it does make a difference by simply measuring OD260, but not a
huge one. Depending upon one's application and usage of the label, that
difference may or may not be acceptable.
I love deadlines. I especially like the whooshing noise they make as
they go flying by.
More information about the Methods