Troubleshooting guide
QIAprep 96 Turbo
34 QIAprep Miniprep Handbook 12/2006
4. Remove the tape from the block. Pipet the lysates from step 3 (850 µl per well) into
the wells of the TurboFilter plate. Unused wells of the TurboFilter plate should be
sealed with tape. Apply vacuum until all samples have passed through.
The optimal flow rate is approximately 1–2 drops/s, which can be regulated by
using a 3-way valve or vacuum regulator (see page 48) between the QIAvac and
the vacuum source.
5. Switch off vacuum and ventilate the QIAvac 96 slowly. Discard the TurboFilter
plate. Transfer the QIAprep plate containing the cleared lysates to the top plate of
the manifold. Seal any unused wells of the QIAprep plate with tape. Replace plate
holder in the base with waste tray. Place the top plate squarely over the base,
making sure that the QIAprep plate is seated securely. Apply vacuum.
The flow-through is collected in the waste tray.
6. Recommended: Switch off vacuum, and wash QIAprep plate by adding 0.9 ml
Buffer PB to each well and applying vacuum.
This step is necessary to remove trace nuclease activity when using
endA
+
strains
such as the JM series, HB101 and its derivatives, or any wild-type strain, which
have high levels of nuclease activity or high carbohydrate content. Host strains
such as XL-1 Blue and DH5α do not require this additional step.
7. Switch off vacuum. Wash QIAprep plate by adding 0.9 ml of Buffer PE to each well
and applying vacuum. Repeat once.
8. After Buffer PE has been drawn through all wells, apply maximum vacuum for an
additional 10 min to dry the membrane.
Important: This step removes residual Buffer PE from the membrane. The removal
is only effective when maximum vacuum is used (i.e., turn off vacuum regulator or
leakage valves if they are used), allowing maximum airflow to go through the
wells.
9. Switch off vacuum, and ventilate the QIAvac 96 slowly. Lift the top plate from the
base (not the QIAprep plate from the top plate), vigorously tap the top plate on a
stack of absorbent paper until no drops come out, and blot the nozzles of the
QIAprep plate with clean absorbent paper. Proceed either to step 10a, or 10b, as
desired.
This step removes residual Buffer PE, which may be present around the outlet
nozzles and collars of QIAprep plate. Residual ethanol from Buffer PE may inhibit
subsequent enzymatic reactions.