mRNA Isolation Kits

[John D. Valentich]

We are beginning a project requiring isolation of poly(A) RNA from intestinal 
mucosa which will be used in Northern analysis.  We have extensive experience 
extracting total RNA from tissue culture cells but have not attempted to 
isolate mRNA.  We are planning to use the Stratagene Quik mRNA isolation kit, 
unless someone suggests a better alternative.  We have been woundering about 
the following issues regarding the use of this kit:

1.  Are columns reusable?  If so, for how many purifications?
2.  How should used columns be stored and how are they regenerated?
3.  Does repeated use of a column compromise mRNA recovery efficiency or other 
isolation parameters?

For those who have experience with the Stratagene or other  mRNA 
purification systems, we would appreciate your insights and suggestions.