When attaching a single reagent to the tubing set, close the clamp of the line you will not be using. Then using the open line, hold the reagent vial in your hand, spike the vial adapter down into the vial, and twist slightly to ensure the vial is fully seated into the vial adaptor.
Invert the vial and place the glass vial in the vial holder at Bag Hanger B. Do not place the reagents into the vial holders by the plastic of the vial adapters.