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Quantiferon Plus TB *






TB Gold; Quantiferon® TB Gold; Interferon-gamma Release Assay for Tuberculosis 

Specimen Type

Whole blood- special tubes from lab.


Special collection tubes available from Referred Dept.(LabCorp) Collection kit (QFT™) Kit contains four tubes1.  Gray-top/white ring(nil) 2. Green-top /white ring (TB1 tube) 3. Yellow-top /white ring (TB2 tube) 4. Purple-top/white ring (mitogen coated). All tubes must be collected for the test. Do not discard box.

Collection Instructions

Because of limited vacuum in these tubes, use a needle and holder (not a butterfly).  If a butterfly is required, first collect other required tubes or use another Vacutainer™ tube to purge the butterfly line of air and then proceed with drawing. Fill tubes to the black fill line on the tube. Do not overfill or under fill. If this happens, immediately redraw a replacement tube. Following proper fill, shake tubes 10 times firmly enough to ensure the entire surface of the tube is coated with blood cells to solulibilize the antigen on the tube walls. Place properly filled and labeled tubes back in box. Do not seal the box containing the tubes before delivering to the lab. Do not centrifuge or refrigerate! 
Specimen can only be collected Sunday –Thursday. Specimens cannot be collected the day before a holiday. 


1 ml x four tubes (see previous instructions)

Additional Information

Used to aid in the diagnosis of both latent and active infection with Mycobacterium tuberculosis. This test has been shown to be accurate in HIV-positive individuals with moderately advanced disease.

Patient Preparation

Specimen Processing Instructions

LAB Processing ONLY: DO NOT Centrifuge. Four tubes will come in a box, (QFT™ kit ) check each tube to ensure each is properly filled and labeled correctly. Place tubes back in the box.  Shake for a few seconds. Attach a lab computer label on the box and place in the incubator (37▫) standing upright in the Microbiology Department overnight.(16-24 hrs.) Leave information for Lab Corp processor on the log sheet.

Quantiferons cannot be sent via the pneumatic tube system.

Transport Requirements

Room temperature ONLY

Specimen Stability

LabCorp must receive specimen within 70 hours after incubation. 

Rejection Criteria

Specimens not collected in special tubes. Centrifuged, refrigerated or frozen specimens. Tubes not labeled correctly.

Reference Range


Critical Value


Test Includes

Quantiferon® Plus TB 


Whole blood interferon-gamma test measuring responses to ESAT-6 and CFP-10 antigens.

Testing Frequency




Reviewed By

Lisa McBride

Reviewed Date



* Reference Lab Test

Reviewed by Lisa McBride on September 18, 2018

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