Procedure1. Pipet 20 μl QIAGEN Protease (or proteinase K) into the bottom of a 1.5 mlmicrocentrifuge tube.2. Add 200 μl sample to the microcentrifuge tube. Use up to 200 μl whole blood,plasma, serum, buffy coat, or body fluids, or up to 5 x 106 lymphocytes in200 μl PBS.If the sample volume is less than 200 μl, add the appropriate volume of PBS.QIAamp Mini spin columns copurify RNA and DNA when both are present inthe sample. RNA may inhibit some downstream enzymatic reactions, but not PCR.If RNA-free genomic DNA is required, 4 μl of an RNase A stock solution(100 mg/ml) should be added to the sample before addition of Buffer AL.Note: It is possible to add QIAGEN Protease (or proteinase K) to samples that havealready been dispensed into microcentrifuge tubes. In this case, it is important toensure proper mixing after adding the enzyme.