A total blood volume of 14-17mL collected in two Roche® cell-free DNA tubes is required. Each tube must be filled to above the minimum file line of 7mL to ensure adequate additive-to-blood ratio. If the minimum volume is not achieved for either tube, use a 21 gauge or larger bore needle and regular syringe to obtain the remaining required blood and top off the tube. To transfer the blood to the tube, uncap the tube, remove the needle, and deposit the blood directly from the syringe into the cell-free DNA tube to reduce hemolysis; do not insert the needle through the rubber stopper. Replace the cap and be sure to gently invert the sample at least 8-10 times. If topping off the tube, it must be filled within 15 minutes from initial tube puncture. Once sampling is complete, the OncoK9 sample must be kept at room temperature and has to be received at the PetDx laboratory within 7 calendar days from the sample draw, otherwise a redraw may be required.