precipitate in NEB T4 Ligase buffer?

[Paul N Hengen]

 In article <3gr9rm$jon at mcmail.CIS.McMaster.CA>
 g9013118 at mcmail.cis.mcmaster.ca (K. Legate) writes:

|: It's the DTT. However, repeated freeze-thawing of ATP does have effects,
|: at least according to one supplier of T4 ligase.
|
| The efficiency of my ligations goes way down after repeated freeze-thaw 
| cycles of the buffer. Adding a small amount of ATP to the mix restores 
| original efficiency.
|
| kyle

...and how is the rATP stored? I keep mine at -20 C. If yours is also frozen
at -20 C, then thawed before adding a small amount to the ligation buffer,
wouldn't the rATP also degrade over several freeze-thaw cycles resulting in
loss of ligation efficiency?

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* Paul N. Hengen, Ph.D.                           /--------------------------/*
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