QuantiFERON-TB (QFT)

Alternate test name

Tuberculosis, Mycobacterium tuberculosis

Lab area

Microbiology - Quantiferon

Method and equipment

ELISA

Expected turn-around time

10 to 14 days

Specimen type

Whole blood

Specimen requirements

Whole blood in 6mL lithium-heparin tube. Please ensure that there is a minimum of 5mL of blood.

Storage and transportation

After collection, blood sample must first be held at room temperature (17–25°C) for a minimum of 15 minutes to a maximum of 3 hours before being placed in the refrigerator (2–8°C).
Specimen may be held in the refrigerator for a further 16 to 36 hours before shipping
Ship on ice packs
Total time from collection to receipt in SickKids Microbiology laboratory cannot exceed 50 hours.
Specimens should be shipped Monday to Friday and received at SickKids by 5pm.

Special requirements

Please fully complete testing requisition. Specimens may be rejected if requisition has not been fully completed at the time of specimen submission.

Read carefully: "Optimal Collection Time/Storage/Transportation/Receipt of Samples" on Page 1 of requisition to be completed.

Blood collection tubes should be between room temperature (17–25°C) at the time of blood filling. Only a Lithium - heparin anticoagulant is acceptable.
After collecting blood, gently mix by inverting several times to dissolve the heparin
The collected blood sample must first be held at room temperature (17–25°C) for a minimum of 15 minutes to a maximum of 3 hours before being placed in the refrigerator (2–8°C).
Specimen may be held in the refrigerator for a further 16 to 36 hours before shipping.
Total time from collection to receipt in SickKids Microbiology laboratory cannot exceed 50 hours

Requisition

QuantiFERON-TB (QFT) - requisition

Background and clinical significance

Quantiferon TB Gold is an in vitro diagnostic test for cell mediated immune response to peptide antigens that simulate Mycobacterial proteins.
Individuals infected with M.tuberculosis (TB) usually have lymphocytes in their blood that recognize these antigens and secrete IFN-gamma that is subsequently detected by ELISA.
This test is an indirect test for detecting latent tuberculosis infection (LTBI).
This test is intended for use in conjunction with risk assessment, radiography and other medical and diagnostic evaluations.
A negative test does not rule out TB.

Disease condition

Tuberculosis