Specimen Requirements

The request slip should indicate AFB culture. A culture and an AFB smear are necessary for the adequate diagnosis of a mycobacteria infection and both will be performed on all specimens submitted for an acid fast workup. The source of the fluid must be noted.

Specimen Type: Sputum, urine, blood, body fluid, stool, tissue, gastric washes

Container/Tube: Sterile container, AFB culture sputum container

Collection Instructions: The culture specimen must be material from the actual infection site. It must be collected with a minimum of contamination from the adjacent tissues, organs, or secretions. Whenever possible, the culture should be obtained prior to the administration of an antibiotic.

A. Sputum:

Specimen Type: Sputum
Container/Tube: Sterile leak-proof container

Volume: 10 mL

Minimum Volume: 5 mL **If additional testing is ordered along with AFB, 15 mL is required, with a minimum volume of 10 mL** 
Collection Instructions: Indicate source. Label with 2 patient identifiers. See also Special Collection Forms - Sputum Collection in the menu on the left

1. Sputum must be first morning specimen.
2. Prior to eating, rinse mouth with water.
3. Expectorate into a sterile cup.
4. Collect 5 to 10 mL of sputum in a sterile container in the morning.*10-15 mL if additional testing required**
5. If the volume of sputum received is less than 1 mL, document on the report.
6. Maximum of 3 expectorated sputum specimens, collected on separate days, will be tested on any one patient.
7. If 2 or more specimens are received on a single day, the specimens will be combined before concentration.
8. Specimens collected by bronchoscopy will be accepted even if the patient has had 3 sputum specimens cultured prior to bronchoscopy.
9. After therapy is initiated, subsequent cultures to follow therapy will be accepted.

Note: An AFB culture sputum container is available from the laboratory. It has a funnel shaped receptacle to aid in collection. The unit also includes a label and the bottom holder provides for the tube to be set in an upright position. The conical inside tube should be removed and the blue screw cap put in place after collection. The funnel shaped receptacle and the bottom holder should be discarded. 

2. Transportation: The specimen should be delivered to the laboratory as soon as possible. If there is a delay in transportation, the specimen should be refrigerated.

B.  Urine:

Specimen Type: Urine
Container/Tube: Sterile container

Collection Instructions: Indicate source. Label with 2 patient identifiers.

1. An early morning, cleanly voided, mid-stream urine specimen collected in a sterile container and sent to the laboratory.
2. Pooled 24 hour urine specimens will not be accepted.
3. A maximum of three specimens, collected on separate days will be accepted.
4. Volumes up to 100 mL will be concentrated by centrifugation for media inoculation.
5. Urine collected in a gray top tube w/boric acid is an unacceptable specimen

Transport Temperature: Refrigerated

C. Gastric Contents:

Specimen Type: Gastric Lavage - Collect if sputum is not obtainable
Container/Tube: Sterile container

Collection Instructions: Indicate source. Label with 2 patient identifiers.

1. Gastric contents are cultured on the premise that they contain sputum which has been swallowed, and are the specimen of choice for patients under 12 years old.
2. Collect gastric contents in a sterile container in the morning prior to breakfast.
3. If the specimen cannot be delivered to the lab within 4 hours for pH neutralization, request a sterile container with 100 mg of sodium carbonate for specimen collection.

Transport Temperature: Refrigerated

D. Other Body Fluids and Material: 

Since AFB may occur in almost any site of the body, types of clinical material other than those previously mentioned may be examined. Specimens of cerebral spinal fluid, pleural fluid (indicate left or right), and pericardial fluid, pus, joint fluid, bronchial secretions, and tissue sections may be submitted for study. The collection of these specimens for AFB are performed as they would be routine bacteriological study.

Specimen Type: Pleural, Pericardial, Peritoneal, Spinal Fluid, Other Body Fluids
Container/Tube: Sterile container

Collection Instructions: Indicate source. Label with 2 patient identifiers.

1. Large volumes are required for optimal processing and results.
2. Up to 100 mL will be concentrated by centrifugation for media inoculation.  Sterile collection containers must be used.

Transport Temperature: Ambient for spinal fluid, refrigerated for all other body fluids.