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Test Code LAB3000 Employee Quantiferon TB Test

Clinical System Name

Employee Quantiferon TB Test



Sample Requirements

Specimen: Whole blood

Container(s): 4 Quantiferon TB Tubes: Nil, TB Antigen CD4, TB Antigen CD8 and Mitogen

Preferred Vol: Fill to black mark on each tube 

Minimum Vol: N/A


Note: Obtain special Quantiferon tubes and specific instructions from Laboratory (987-2102).  If butterfly needle is used, a "purge" tube should be collected to ensure tubing is filled before filling Quantiferon TB Gold tubes. After collection, shake tubes 10 times to coat the inner surface and deliver to the laboratory at RT.

Tubes can be drawn in any order, but fill volume to black fill line on label is crucial.  Overfilled/underfilled tubes will be rejected.


Processing Instructions

Reject due to: Overfilled/underfilled tubes

Spin: N

Aliquot: N

Temp: RT

Storage location:  Incubation in set intervals by CPA.  Refer to Quantiferon (QFTB) Incubation Process in Lucidoc for details.  After incubation, samples are stored in the CPA refrigerator.

Off-site collection:  Specimens must be collected in four Quantiferon TB Gold tubes, received and incubated within 16 h of collection.  Ship at RT.


Specimen Type Temperature Time
  Room temp 16 h
  Refrigerated N
  Frozen N



STAT Performed TAT
N T, F 1 w

Call the Chemistry Laboratory (206-987-2565) for requests outside of stated availability.

Samples are incubated for 18 hours prior to running on the analyzer.  QFTB samples must be received at the main campus laboratory prior to 4pm to make the next day's run.


Performing Laboratory

Seattle Children's Laboratory    



Department:  Chemistry

Location: Chem West

Phone Number: (206) 987-2617





Method: Interferon-gamma release assay

Analytical Volume:


Reference Range

Expected value: Negative

Individuals on steroids may have indeterminate results. For indeterminate-low mitogen results a redraw is recommended.