9
Plasmid DNA purification
MACHEREY-NAGEL – 08/ 2013, Rev. 01
•
High concentration: Perform one elution step with 60 % of the volume
indicated in the individual protocol. Concentration of DNA will be higher than
with standard elution (approx. 130 %). Maximal yield of bound nucleic acids is
about 80 %.
•
High yield and high concentration: Apply half of the volume of elution buffer
as indicated in the individual protocol, incubate for 3 min and centrifuge. Apply
a second aliquot of elution buffer, incubate, and centrifuge again. Thus, about
85–100 % of bound nucleic acids are eluted with the standard elution volume
at a high concentration.
Elution Buffer AE (5 mM Tris/HCl, pH 8.5) can be replaced by TE buffer or water as well.
However, we recommend using a weakly buffered, slightly alkaline buffer containing no
EDTA, especially if the plasmid DNA is intended for sequencing reactions. If water is
used, the pH should be checked and adjusted to pH 8.0–8.5 since deionized water
usually exhibits a pH below 7. Furthermore absorption of CO
2
leads to a decrease in
pH of unbuffered solutions.
