$34 | CPT Code: 87389 | Serology Lab
Specimen collection guides
Methodology
Interferon-gamma release assay (IGRA)
Acceptable specimen(s)
- Blood sample collected in a lithium heparin blood tube (green top) to the fill line (6 mL).
- It can sometimes be difficult to fill a vacutainer blood collection tube at altitude. If you cannot fill the entire tube, submit a second tube for the patient.
- Blood samples can also be collected in the QuantiFERON-TB Gold Plus collection tube set (purple, green, yellow, and gray top). Collect 1 mL of blood in each tube.
Specimen labeling
A minimum of two of the following are required on the specimen label:
- Patient first and last name
- Date of birth
- Medical record number (MRN) or patient identification (ID)
The following information is optional, but highly preferred:
- Collection date
- The chain of custody number, if ordered through LabOnline
The lab will not process samples without appropriate identifiers on the label. Be sure the information on the label matches what is listed on the test order.+
Label cold mailer or coolers and outer hard-sided shipping containers using the CDPHE-provided pre-printed TB labels. Place a label on the top and one of the sides of the container. Pre-printed labels can be requested in the public health supply order form.
Specimen stability
- 48 hours at refrigerated temperatures (2-8°C).
- The lab must receive the sample within 48 hours of collection.
Turnaround time
- Five (5) business days.
- Results will be available in LabOnline.
Rejection criteria
Incomplete or missing test order, incomplete specimen labeling, specimen collected in expired collection kits, quantity not sufficient, hemolysis, lipemia, received out of hold time, received out of temperature.
Ordering in LabOnline
- Profile: Tuberculosis Testing, Microbiology
- Testing type: QuantiFERON TB Gold
- Matrix: Blood
Additional sample submission information
Contact information
- Client services: cdphe_labcoordinators@state.co.us
- Serology Lab: cdphe_serology_lab@state.co.us