Genomic DNA is purified from blood using one of 2 alternative procedures, using a centrifuge or using a vacuum manifold and centrifuge (see flowchart " Procedure"). The universal DNA purification system allows compatibility with other in vitro diagnostic products (see " Workflow").
The EDTA- or citrate-containing blood sample (200 µl) is lysed in the presence of QIAGEN Protease and lysis buffer at 56°C for 10 minutes. Ethanol is then added to the lysate to optimize binding of DNA to the QIAamp membrane. The lysate is applied to a QIAamp Mini spin column, which is then centrifuged or subjected to vacuum pressure. DNA binds to the QIAamp membrane in the spin column, and the rest of the lysate passes through. Bound DNA is efficiently washed by 2 different wash buffers, which are also drawn through the QIAamp membrane by centrifugation or vacuum pressure. The QIAamp membrane is then dried by centrifugation. Elution buffer (50–200 µl) is applied to the QIAamp membrane and, after a 1-minute incubation, the spin column is centrifuged to elute pure DNA.
Purification of DNA using the QIAamp DSP DNA Blood Mini Kit can be fully automated on the QIAcube. If automating the QIAamp DSP DNA Blood Mini Kit on the QIAcube instrument, the instrument may process fewer than 50 samples due to dead volumes, evaporation, and additional reagent consumption by automated pipetting. QIAGEN only guarantees 50 sample preps with manual use of the QIAamp DSP DNA Blood Mini Kit.