Laboratory Test Information Guide

Details for Mycobacterium Culture

Test Name: Mycobacterium Culture
Alternate Name(s): Acid fast Bacilli Culture (AFB)
TB Culture
Laboratory: Microbiology (VH)
Specimen Type: -Abscess/aspirate fluid
-Body Fluids (pleural, pericardial, peritoneal, etc.)
-Bone Marrow
-Gastric Lavage
-Respiratory (includes bronchial alveolar lavages, sputum or tracheal aspirations)
Collection Information: Collect samples aseptically. Swabs are not accepted. Do not use fixatives or preservatives. Do not use waxed containers.

Abscess or Aspirate Fluid - Collect as much material or fluid as possible in a sterile container

Blood - Collect into a 6 mL Dark Green (Sodium Heparin) top Vacutainer tube. DO NOT SPIN

Body Fluids - Collect as much as possible (10-15 mL minimum) in a sterile container.

Bone - Collect in a sterile container.

Bone Marrow - Collect into 6 mL Green top Vacutainer tube or sterile container.

CSF - Collect a minimum of 2mL in a sterile container. Specimens <0.5 mL will be rejected

Faeces Collect a minimum of 2 grams in a sterile container.

Gastric Lavage - Obtain Gastric Lavage Transport media from the Microbiology Laboratory. Collect fasting, early morning sample to recover sputum swallowed during sleep. Following collection, the sample must be neutralized immediately by transferring it to the transport container which contains sodium carbonate.

Bronchial Alveolar Lavages - Collect a minimum of 5 mL in a sterile container. Submit a post-bronchoscopy sputum as well.

Sputum - Collect 5-10 mL of expectorated or induced sputum in a sterile container. Patient can expectorate several times per collection to achieve minimum volume.
Ensure patient does NOT rinse mouth with tap water before expectoration or expectorate saliva or postnasal discharge. Do not pool samples.

Tracheal Aspiration - Collect as much as possible in a sterile container.

Tissue - Collect 1 gram of tissue in a sterile container. Select caseous portion if available. A small amount (<1 mL) of sterile saline may be added to keep specimen from drying. Tissue submitted in anaerobic transport is not acceptable for culture.

Urine - Send minimum 40 mL volume of first morning urine (midstream or catheter collection) in sterile container.
(Do not send in a Vacutainer with preservative).
Test Schedule: Referred out weekdays to Public Health Laboratory.

Microscopic results are reported as soon as possible. Culture requires up to 8 weeks.

Positives are reported upon detection.
Turnaround time from when specimen
is received in testing laboratory:
8 weeks
Reference Range:  
Effective Date: 2010-06-10
Revised Date: 2020-04-24
Critical Value:  
Interpretive Comments:  
Special Processing:  
Method of Analysis: Microscopy, culture, PCR
Critical Information Required:  
Storage & Shipment: Do not refrigerate blood for mycobacterial culture, hold at room temperature. Refrigerate all other specimens whenever possible if transport to the laboratory or specimen processing will be delayed more than one hour.

The specimen must be received within 24 hours of collection.
System Codes: 
Referred To: Public Health Laboratory

Questions? Comments? Contact Laura Gopaul