Bio-Rad Quantum Prep Plasmid Kits - Manual (Page 10)

The final formulation of the wash buffer contains 50% ethanol.
To achieve this, add 63 ml of ethanol to the wash buffer before
first use of the Quantum Prep kit.
8. Remove the spin filter from the 2 ml tube, discard the filtrate at
the bottom of the tube, and replace the spin filter in the same
tube. Add 500 µl of wash buffer and wash the matrix by
centrifugation for 30 seconds.
9. Remove the spin filter from the 2 ml tube, discard the filtrate
at the bottom of the tube and replace the spin filter in the
same tube. Add 500 µl of wash buffer and wash the matrix
by centrifugation for a full 2 mins to remove residual traces
of ethanol.
10. Remove the spin filter and discard the microcentrifuge tube. Place
the spin filter in one of the 1.5 ml collection tubes supplied with
the kit or in any standard 1.5 ml microcentrifuge tube that will
accomodate the spin filter. Add 100 µl of deionized H
2
O or TE.
Elute the DNA by centrifugation for 1 min at top speed.
11. Discard the spin filter and store the eluted DNA at -20°C.
6