Page 19 - SRL Diagnostics Directory of Services

QUANTIFERON ® - TB GOLD

PLUS SAMPLE COLLECTION

Technical Note for Sample Collection and Mixing

• Collect 1Ml of blood by venipuncture into each QFT-Gold plus blood
collection tube.
[NIL, TB1, TB2 and MITOGEN] (Total 4 tubes).
• Thorough mixing will dissolve the heparin, preventing clotting, and
allow resolubilization of the stimulating antigen.

• Mixing is performed by shaking the tubes ten (10) times just firmly
enough to ensure that the entire inner surface of the tube is coated
with blood.
• Over-energetic shaking may cause gel disruption and could lead to
aberrant results.

Sample Incubation at Collection Site

• Prior to incubation, maintain tubes at room temperature (22°C ± 5°C)
do not refrigerate or freeze the blood samples.
• The tubes must be transferred to a 37°C ± 1°C incubator as soon as
possible or within 16 hours of collection. **Incubate tubes upright at
37°C for 16–24 hours**
• After incubation centrifuge the tubes for 15 minutes at 2000 to 3000
rpm. The gel plug will separate the cells from the plasma.
If this does not occur, the tubes should be re-centrifuged.
• Ship the tubes to testing laboratory (within 3 days). Maintain tubes at 4– 27°C.

It is “NOT MANDATORY” to separate the plasma.
(If plasma is separated from QFT tubes send the tubes at
below -20°C
with correct labeling of tubes i.e. .NIL, TB1, TB2, and MITOGEN)
• Label the tubes and TRF appropriately. (Sample collection DATE,
TIME and INCUBATION status)
• Technical tip: Label tubes and TRF as “INCUBATED”.

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