hi

as i understand you have two columns from two different kits >>>> RNeasy mini kit it must be used first for extraction of total RNA from cell and then you can use minelute column at the final of extraction to elute your RNA as pure and concentrated and you can store your RNA in it 

hope this will help you 

best of luck  

Dear Rachel,

The difference is basically the elution volume. Both are for RNA isolation and clean up procedures. But minielute column should are a little more expensive, should be storage in +4 oC. The great advantage is that you can elute your RNA in only 14 microlitres, which allow you to have an RNA much more concentrated, something that it is very convenient for many downstream reactions. Never storage the RNA in any column, the RNA should be isolate as fast as possible and storage at -80 if you do not plan to use it in short term.  

I am pretty sure the silicon membrane is the same, not sure about the binding capacity.

Personally, I prefer to elute in a large volume and then vacuum concentrate. Nothing bad happens to good RNA even at 45oC for half an hour.

I would call QIAGEN tech support, they are quite helpful, although in writing they might be bound to say "do not use" as it will increase their sales...