You should add some salt when you anneal!!!
The duplex is highly negatively charged, so adding even a
small amount (like 10mM NaCl) will help with charge
screening, thus making the two strands less repellant to
each other. Buffer is also always a good idea. At low pH
and high temp you'll
Hi Artem Evdokimov
Thank you for the mail. I have synthesized DMT-on
oligos in our laboratory. Deprotection was performed
treating with ammonium hydroxide for 15 hours at 55C.
Then, DMT-on oligo was separated from off using
RPHPLC.
DMT was cleaved by treating with 20% glacial acetic
acid for one
Check the purity of the DNA in solution:
A(260 nm)/A(280) = 1.8 for fully deprotected DNA, and you should see a
nice clean simple curve with a peak very close to 260 nm.
Check it on a denaturing gel. Smearing indicates incomplete
deprotection. This is usually the cause of solubility
Hi
Thank you for the mail.
It seems your correct. A(260 nm)/A(280) of one oligo
is around 1.0 and peak is around 272. Other
oligo's(260 nm)/A(280) is around 1.5.
Can I know what is the absorbance peak of base
protecting N-benzoyl group.
Is it possible to do deprotection of base after mixing
, 2008 1:01 PM
To: CCP4BB@JISCMAIL.AC.UK
Subject: Re: [ccp4bb] query on DNA-protein complex preparation for
crystallization
Hi
Thank you for the mail.
It seems your correct. A(260 nm)/A(280) of one oligo
is around 1.0 and peak is around 272. Other
oligo's(260 nm)/A(280) is around 1.5.
Can I know what
Hi,
How did you synthesize the DNA? I assume external vendor (so few people make
their own these days)? How was the DNA purified? Sometimes if only a
'desalting' step is used there may be 'other chemicals' in the mix. Also,
what pH was your DNA at, and in what buffer (if any)? If your DNA
