Test Overview
Test Methodology

Microscopic Exam

Test Usage

Determine presence of mycobacteria

Reference Range *

No mycobacteria seen on smear. Positive smears will be quantitated and reported as: rare (1-3 bacilli in entire smear), few (4-9 bacilli in entire smear), moderate (>10 bacilli in entire smear), or numerous (1 or more bacilli per high power field).

Test Limitations

Cultures are more sensitive than smears. The smear may be negative when the culture is positive.

Test Details
Days Set Up
Monday - Saturday
Analytic Time

Preliminary results are reported in 12-24 hours, Monday - Saturday. The health care provider will be notified of positive smears. STAT smears are not done routinely and are not recommended on unconcentrated specimens due to the low number of organisms. Contact the MLabs office if there is a special need for a STAT smear.

Soft Order Code
MiChart Code
Acid Fast Bacillus Smear
  • AFBS
  • Atypical Mycobacteria Smear
  • Auramine Stain
  • Fluorescent Stain, AFB
  • Kinyoun Stain
  • Mycobacteria Smear
  • TB Smear
  • Acid Fast Bacilli Smear
STAT Availability

Supervisory approval required for STAT AFB Smear.

Specimen Requirements
Collection Instructions

Appropriate specimen for smear is the same as for culture. For optimum recovery, send immediately. If specimen must be stored, refrigerate immediately after specimen collection; specimen may be refrigerated up to 72 hours. Do not incubate. Indicate specimen source, collection date/time, current antibiotic therapy, and clinical diagnosis.

Normal Volume
Same as for culture of specific site. Minimum of 0.1 ml.
Minimum Volume
Same as for culture of specific site. Minimum of 0.1 ml.
CPT Code
Fee Code