RE digest X - Ligation - RE Digest Y (purif. needed?)

[Javier Alzerreca]

Hello,

We have a fragment cut with EcoRI - both ends. This fragment is pure.
If we proceed to a ligation reaction, (for circularization) do we need 
to purify the DNA from this reaction before a new RE digest with a 
different enzyme? "Will T4 DNA ligase affect the second RE digest?"

Purification is best, but we think we have little DNA and we don't want 
to loose it in a phenol-chloroform extraction. The same may apply for 
other purification techniques.

Thanks for any help.

 
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5' J A V I E R   A L Z E R R E C A   B.S.    ====--------- ---------====
   | |   | | |   | | | | |   | | |   | |        javier at mendel.usu.edu
  .S.B   A C E R R E Z L A   R E I V A J  5' ====--------- ---------====