Fragment prep. using QiaTip?

QIAGEN qiagen at
Fri Mar 22 11:17:34 EST 1996

bjorn eriksson <bjoeri at wrote: 

>If i want to purify dna from a slice of low melting agarose using Qiagen
tip >20, in >what buffer should i load the melted agarose to maximize
binding to the >matrix?

Dear Dr. Eriksson,

We have an old protocol for DNA extraction from low-melting point agarose
with QIAGEN-tip columns that was published in the QIAGENOLOGIST (1990). We
would be happy to fax it to you. Briefly, it calls for melting the gel
slice in Buffer QB (the same as QBT but without 0.1% Triton), which you
will have to make up yourself. Solid urea must then be added to prevent
the agarose from regelling on the QIAGEN-tip column. The column is
preequilibrated with the usual Buffer QBT and loading, washing, and
elution proceed as usual, except that Buffer QB is substituted for Buffer
QC in the wash step. After elution, precipitation of the DNA fragment with
isopropanol is enhanced by lowering the pH of the eluate with sodium
acetate, incubating on ice, and if necessary, adding a glycogen carrier. 

This is a very old QIAGEN procedure, which has now been replaced with
better and simpler products which do not require the use of low melting

Technical Service in Germany can be reached at: 02103-892-240 


Paul Todd, Ph.D.
Technical Service Manager

Temporary e-mail address: qiagen at

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