Tb h-IFN Quantiferon Gold (Blood)

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Testing Laboratory

Auckland Te Toka Tumai | Auckland Hospital

Department

Virology

Delphic Registration Code (Alpha Code)

QTBG

Test Code (Numeric Code)

2851

Laboratory Handling

Phlebotomy

The QuantiFERON assay-specific collection tubes (4 set), as supplied by the laboratory, must be used. No other tubes are acceptable. The 4 tubes are: Nil (grey cap), TB1 antigen (green cap), TB2 antigen (yellow cap), and Mitogen (purple cap). 1 Collect sample according to the tube colour order of collect (grey, green, yellow, purple) 2. Collect 1mL blood (up to the black mark) into each of the Quantiferon Gold tubes supplied. 3. Mix tubes thoroughly by inversion 10 times. Ensure the entire inner surfaces of tubes are coated with blood. 4. Place patient sticker on top of the tube manufacturer label. It is paramount to leave the side of the tube clear and black mark uncovered. Without label, handwrite patient details ensuring minimum two points of ID present. 5. Send to ALSS (Specimen Services), LabPLUS.

Transport

Do not refrigerate or freeze the original blood specimens prior to incubation. Samples need a 24 hour incubation period before testing can proceed.

Registration

QTBG

Separating

Original blood tubes that have had no incubation or centrifugation 1. Arrival at LabPLUS must be no later than 1800 hours (6pm), Monday to Friday on the day of collection. 2. Do not refrigerate or freeze the specimens 3. Do not centrifuge the specimens 4. As soon as possible after ALSS registration, transfer to Microbiology for 37 o C incubation. Original blood tubes that have been incubated and centrifuged 1. Register in ALSS and transfer to Microbiology 2. Microbiology staff will identify the blood specimens have been centrifuged and will place in the upright glass-fronted refrigerator in their specimen put-up area Separated plasma specimens referred to LabPLUS: Protocol to follow 1. Do not refrigerate or freeze the original blood specimens prior to incubation 2. Mix tubes thoroughly by inversion 10 times. Ensure the entire inner surfaces of the tubes are coated with blood 3. Incubate within 16 hours of collection at 37oC for 16 to 24 hours 4. After centrifugation at 3000g/15 minutes, separate plasma by drawing off with a pipette into labelled daughter tubes. Ensure daughter tubes are clearly labelled as to Nil, Tb antigen and Mitogen 5. Send to LabPLUS maintaining cold chain storage (i.e. use chiller packs) 6. Register in ALSS and transfer to Microbiology 7. Microbiology staff will identify the specimens are separated plasmas and will place in the upright glass-fronted refrigerator in their specimen put-up area.

Sample Stability

Please refer to additional referral/aliquoting information

Synonyms

Tuberculosis (TB) Blood Test

Turnaround Time

10 days

The ELISA test is batched and performed 3 times a week. Tests are not processed on weekends or statuatory holidays.

Specimen Type

  • Whole Blood

Specimen Requirements

Tube/Container Type:

Preferred
  • QTGB Nil (Grey Cap)
  • QTBG TB1 antigen (Green Cap)
  • QTBG TB2 antigen (Yellow Cap)
  • QTBG Mitogen (Purple Cap)
Preferred Sample Volume (ml)

1

Minimum Sample Volume (ml)

1

Paediatric Specimen Requirements

Tube/Container Type:

Preferred
  • QTGB Nil (Grey Cap)
  • QTBG TB1 antigen (Green Cap)
  • QTBG TB2 antigen (Yellow Cap)
  • QTBG Mitogen (Purple Cap)
Preferred Sample Volume (ml)

1

Minimum Sample Volume (ml)

1

Pre-testing Requirements

Tb-Quantiferon Gold specific tube sets:
How to obtain tubes for customers both inside and outside the Auckland region

Internal
Contact Lablink x22000
Monday - Friday: 8am - 3.30pm
Tube sets are unavailable outside these hours.

External
Email your Quantiferon TB ordering form to LabLINK (lablink@adhb.govt.nz).
Quantiferon TB ordering forms are available from LabLINK 0800 522 7587 during business hours.

Collection procedure:

1. Collect sample according to the tube colour order of collect (grey, green, yellow, purple)

2. Collect 1mL blood (up to the black mark) into each of the Quantiferon Gold tubes supplied.

3. Mix tubes thoroughly by inversion 10 times. Ensure the entire inner surfaces of tubes are coated with blood.

4. Place patient sticker on top of the tube manufacturer label. It is paramount to leave the side of the tube clear and black mark uncovered. Without label, handwrite patient details ensuring minimum two points of ID present.

5. Send to ALSS (Specimen Services), LabPLUS

Additional Specimen Information

Test is invalid if volume is greater or less than 1mL, or tube colour order of collect is not in right sequence.

Last updated: 13/05/2026