Specimen Type/Requirements

QuantiFERON (QFT) TB Gold 4 Tube Kit

Collect 1 mL of blood into each of 4 tubes.

Tubes may fill slowly. The use of a syringe may ensure correct blood volume. Hold tube on needle for 2-3 seconds after flow ceases. When the tube is upright, blood must be within the black indicator line on the label. (Figure 1)

(Figure 1)

If using butterfly collection device: first collect other required tubes or prime the tubing with a “waste” tube to remove the air and then proceed with collecting the 4 QuantiFERON tubes.

The QuantiFERON tubes are manufactured to draw 1 mL of blood, the black indicator line indicates a range of 0.8 to 1.2 mL. If the level of blood is outside of the black indicator line, another blood specimen must be collected. Over- or under-filling tubes may lead to erroneous results.

Specimens with volumes outside of the black indicator line will be rejected.

Draw order of tubes is:

1. Nil control (grey)

2. TB1-Antigen (green)

3. TB2-Antigen (yellow)

4. Mitogen Control (purple)

Immediately after filling, shake the tubes firmly 10 times (enough to ensure the inner surface of each tube is coated in blood) to solubilize antigens on the tube walls.

Caution: Over-energetic shaking may cause gel disruption and could lead to aberrant results.

Label tubes appropriately. The label should be placed below colored QuantiFERON band so the blood volume and black indicator lines are visible on all 4 collection tubes. (Figure 2)

(Figure 2)

Maintain tubes between 17–25°C (Room Temperature) at the time of collection until incubation.

Do not refrigerate or freeze.

PROCESSING INSTRUCTIONS:

Option 1:  NOT INCUBATED

• Do not centrifuge unincubated tubes.
• Send tubes unspun at room temperature to arrive at the performing lab within 16 hours of collection.
• Clearly label tubes: NOT INCUBATED
• Stability:  Not incubated/unspun – Room Temp 16 hrs

Option 2: INCUBATED

• Within 16 hrs of collection, incubate tubes in upright position in a 37 Degree incubator at the collection site for 16 – 24 hrs.

• Spin down samples at 2000-3000g for 15 minutes so gel barrier rises to separate cells and plasma.
• Do not aliquot specimens from tubes. Send in original tubes.
• Clearly label tubes: INCUBATED
• Stability: Incubated/spun – Room Temp:  3 days   Refrig: (preferred) 28 days    

Test is affected by gross hemolysis, lipemia, and icterus.