AnMed Laboratory Services


AFB Smear  (AFB S)

Synonyms:  TB Smear, Acid Fast Smear, Mycobacterial Smear, Ziehl-Nelson Smear
Specimen:  Sputum- 10 mL; references recommend sputum be collected first morning on 3 separate days but when timing is an issue, 3 specimens at least one of which is first morning collection, may be submitted. Body Fluids or Urine- 50 mL; prefer 3 urine specimens collected on 3 separate days. CSF- 5mL; specimens should be collected in a sterile CSF tube.
                        Volume:  10 mL sputum, 50 mL urine or body fluid, 5 mL CSF
Minimum Volume:  5 mL sputum, 5 mL urine, 1 mL CSF
Collection:  Refrigerate specimen at 2-8°C and transport to the laboratory as soon as possible after collection.
Rejection Criteria:  Dry swab specimens; blood or bone marrow or less than 2 mL of fluid; improper labeling.
Reference Range:  No acid fast bacteria seen.
Methodology:  Microscopy
Test Use:  Detection of acid-fast bacilli in clinical specimens.
Additional Information:  Smears are not performed on blood/bone marrow or when <2 mL of fluid are sent. Smears from concentrated respiratory specimens have increased sensitivity.
Testing Includes:  Preparation and examination of direct and concentrate smears by Ziehl-Neelsen and Auramine stains.
Testing Facility:  AnMed Laboratory