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Mycobacteria (AFB) Blood Culture

Ordering Info & Methodology

Test Code

Cerner Synonyms


Culture AFB Blood, AFB Blood Culture, AFB Blood C&S, Mycobacterial Culture, Mycobacterial, tb, tuberculosis, ntm, afb

Turn Around Time


All specimens will have an acid-fast screening smear performed along with mycobacterial culture. Specimens are concentrated and processed Monday through Saturday (except statutory holidays) at approximately 0900 hours.

Ordering Guide

Specimen Requirements

Sample Type

Collection Container

Alternate Collection Containers

Sputum, Bronchoscopy specimens, Biopsy specimens, Pleural fluid

C&S Container (unless otherwise instructed)

Add on stability
This is the length of time after sample collection that this analyte is stable. Test can be added to a previously collected sample if the time since collection is less than the add on stability time.

Minimum Volume

Add On Stability

Collection and Shipping Requirements

Reference Intervals

Female Reference Interval

Age Category
Reference Interval

Male Reference Interval

Age Category
Reference Interval
Additional Notes

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Measurement Uncertainty (MU)
Every laboratory value is an estimate of the true concentration of substance. MU is the 95% confidence interval around that estimate. 95% of the time, the true concentration will be within the range of the reported value ±MU. This value is based on analytical variability (precision) and does not reflect other factors such as sample collection and handling which may also affect the result.


Reported sodium = 140 mmol/L
Sodium MU = 1%
Expanded uncertainty = 140 mmol/L ± 1% or 140mmol/L ± 1.4 mmol/L
Interpretation - the true value of sodium in the sample is in the range 138.6-141.4 mmol/L, with 95% confidence.

Measurement Uncertainty

STAT AFB requests are not offered on a routine basis, and will only be considered after consultation with the Medical Microbiologist.

Please specify whether TB is suspected versus other Mycobacterium species.

Special Instructions:

  • Bone Marrow:

    see Bone Marrow culture

  • Blood Culture:

    see Blood Culture

  • Sputum:

    Please collect an early morning specimen on 3 consecutive days.  Alternatively, for IPAC purposes, collect 3 specimens within 24 hours with a minimum time span of 8 hours between collections.  Submit each specimen separately.

  • Gastric Washing:

    must use a KB-treated container.  This container holds a buffer to neutralize stomach acid.  Optimal time for collection is early in the morning, before meals.  Submit no more than 100 mL of 3 fasting specimens collected on consecutive days.  Refrigerate after collection.

  • Urine:

    Collected early morning specimens taken on 3 consecutive days.  Do not split one specimen into 3 containers.  Do not submit 24-hour urine collections.

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