The TB Gold specimen collection kit includes four collection tubes - Nil (gray top), TB antigen 1(green top), TB Antigen 2 (yellow top) and Mitogen (purple top), a transport bag, and instructions for collection of the QuantiFERON samples. Collect 1 mL of blood into each of the four collection tubes; a black mark on the side of the tubes indicates the 1 mL fill volume (0.8 mL - 1.2 mL is acceptable for testing). Due to the low volume of draw, the vacuum in the tubes is minimal and the tube fills slowly; to ensure the correct volume is drawn, keep the tube on the needle for 2-3 seconds once the tube appears to have completed filling. The use of butterfly needles is discouraged. If a butterfly needle is used, utilize a waste tube to fill the butterfly line prior to filling the QuantiFERON tubes. Immediately after filling tubes, shake them ten (10) times just firmly enough to ensure the entire inner surface of the tube is coated with blood. Label each tube with the appropriate patient identifiers and collection time.
Process based on transport:
1. Transport at room temperature; do not refrigerate or freeze. Do not centrifuge the specimens. Specimens are accepted by the chemistry laboratory 24 hours a day, 7 days per week. Samples should be received in the lab within 8 hours of collection.

2. If specimen transport cannot be arranged for samples to arrive in the chemistry laboratory within 8 hours of collection, the specimens must be incubated as soon as possible and within 8 hours of collection. Incubate tubes upright at 37 degrees C for 16 to 24 hours (DO NOT use a heating block for incubation). Label tubes as "incubated", refrigerate and send to MLabs within 3 days.