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Acid Fast Bacilli (AFB) Culture - Blood (Lab 001044)
Test Mnemonic:

C MAF includes testing for both AFB and Fungus

C MBLD is AFB only

Specimen Requirements:

It is recommended that the specimen be inoculated at bedside. Most commonly, a syringe with a BD Luer-Lok brand tip is used to draw the specimen. If appropriate, a BD Vacutainer?® brand Needle Holder and a BD Vacutainer brand Blood Collection Set, BD Vacutainer Safety-Lok™ Blood Collection Set or other tubing “butterfly” set may be used. Prior to inoculation, the medium fill volume should be noted on the label with a pen or marker to indicate the starting point of specimen collection. When the desired 3–5 mL of blood has been drawn, the flow should be stopped by crimping the tubing and removing the needle from the BD BACTEC vial. The BD BACTEC vial should be transported as quickly as possible to the laboratory.


BD Bactec Myco/F lytic bottle

Minimum Volume:

3mL is the minimal volume for optimal recovery


Room temperature; Transport to Microbiology Lab ASAP

Specimen Preparation:

The specimen must be collected using sterile technique to reduce the chance of contamination. The range of blood volume for optimum recovery obtained at 3 mL to 5 mL. Bottles should be examined for evidence of contamination such as cloudiness, bulging or depressed septum, or leakage.



Transport to Microbiology Lab ASAP

Causes for Rejection:

Cultures from same source submitted within 7 days of previous collection.

Mislabeled, Under-labeled, or improper transport/ collection. 

Specimens must be labeled. Loose labels placed in the bag or outside of the bag will not be accepted and will be considered under-labebeled. 

Reference Range:

No Acid-fast bacilli isolated 

(If order is C MAF)- No Acid-fast bacilli and no fungi isolated. 

Turnaround Time:

6 weeks. 


Bottles are continuously agitated and incubated in the BD BACTEC FX. Decreases in oxygen due to microorganism metabolism and growth will trigger positive bottle alert. 


Clinical Microbiology


AFB Blood Culture

MAC Blood Culture

Blood culture - Mycobacteria


Clinical Indication:

Suspected Mycobacterial infection of bloodstream

Patient Preparation :

Prep patient and follow blood culture collection guidelines according to UTMB's Evidence based practice and policies. 

CPT 4 Code:

87116, additional codes as indicated


Positive cultures with any organism are critical values and the LIP will be notified.

DO NOT COVER THE BAR CODE LABEL ON THE BOTTLE. Place EPIC label in same direction next to bottle barcode. Both are needed for the BACTEC FX instrument. 

When ordering tests for which Medicare or Medicaid reimbursement will be sought, physicians should only order tests that are medically necessary for the diagnosis or treatment of the patient. Components of the organ or disease panels may be ordered individually. The diagnostic information must substantiate all tests ordered and must be in the form of an ICD-10 code or its verbal equivalent.
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