Stability of Qiagen kits - (Jul/29/2009 )
Anyone know how stable the Qiagen minikits are beyond their sell by date. Have some out of date kits but dont want to risk using them on valuable samples. Does the lysis bufer go off?
DSLJ on Jul 29 2009, 08:58 AM said:
We've never had a problem with kits. Sometimes we go through them fast, other times we don't, and they seem to be about the same. But that all depends on how must past the date they are.
You don't have any less valuable samples to test them on?
If the buffers were stored with the caps TIGHTLY closed you should not have any problems.
The other option could be bad columns. Set up a test with any sample you have sitting around (I'm assuming you mean plasmids?) for yield. Along with that try running 100ul 3M NaOH over an empty column before loading your sample...no need to wash with anything before loading sample. If your yields are much higher for the NaOH column then your columns are bad. The NaOH will not harm your sample, no worries there.
From my experience the columns can indeed turn bad. I always use the most recent lot for precious samples. If you have only old columns, better test them first.