Understanding Your Laboratory Test: A Patient's Guide
This test examines semen under a microscope using a special stain to detect acid-fast bacteria, primarily Mycobacterium tuberculosis, which can cause genital tuberculosis.
{"The test uses acid-fast staining to identify bacteria that cause tuberculosis in the reproductive system","It helps diagnose genital tuberculosis, which can affect fertility","Results are typically available within 1-2 days","A positive result requires further confirmation and treatment","The test is performed on a semen sample collected at a medical facility"}
Key facts at a glance
- LOINC
- 88157-3
- Short code
- AFBSEM
- Synonyms
- Acid fast Stn Smn
- Category
- chemistry
- Sample
- serum
- Container
- Sterile, wide-mouthed, leak-proof plastic container (urine specimen container or dedicated semen collection container). Do not use glass containers.
- Units
- N/A
- Ref low
- 10
- Ref high
- 40
- Critical range
- — – 500 N/A
- Fasting
- false
- Population
- adult
- Sex
- male
- Age range
- ≥ 18 years
- Method
- acid-fast-stain
- CPT
- 87070
- SNOMED
- 122442003
- Specimen volume
- Minimum 1 mL, preferably 2-5 mL of ejaculate
- Stability
- Process within 2 hours of collection if room temperature. If delay exceeds 2 hours, refrigerate at 2-8°C and process within 24 hours. Do not freeze semen sample for acid-fast stain.
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 24–72 hours
- Order
- routine
What is this test and why has my doctor ordered it for me?
The Acid-Fast Stain test on semen is a laboratory examination that uses a special staining technique called Ziehl-Neelsen or Auramine staining to detect acid-fast bacteria, particularly Mycobacterium tuberculosis (the bacteria that causes tuberculosis). This test helps doctors identify if tuberculosis has affected the reproductive organs, which can impact fertility and reproductive health.
How is the sample for this test collected, and what can I expect during the process?
A semen sample is collected through masturbation into a sterile container at a healthcare facility or laboratory. It is important to follow specific instructions regarding sexual abstinence (typically 2-5 days) before sample collection to ensure accurate results. The sample must be kept at body temperature and delivered to the laboratory within a short timeframe, usually within one hour of collection.
What happens to my sample once it arrives at the laboratory for testing?
In the laboratory, the semen sample is spread onto a slide and treated with a special stain (carbol fuchsin). Acid-fast bacteria retain this stain and appear red-pink under the microscope (for Ziehl-Neelsen stain) or fluorescent yellow-green (for Auramine stain). The technician then examines the sample under a microscope to look for these characteristic bacteria.
Are there any risks or side effects associated with this test that I should know about?
There are no direct risks or side effects from the test itself since it only requires a semen sample. The collection process is non-invasive. Some men may feel uncomfortable or embarrassed about providing the sample, but healthcare staff are trained to handle this professionally and respectfully.
Reference range
Adult: 10-40 U/LN/A
Patient should abstain from ejaculation for 48-72 hours before sample collection. Collect semen via masturbation into a sterile, wide-mouthed, screw-top container. Avoid use of lubricants, condoms, or spermicidal agents that may contaminate sample. First void urine should be avoided in sample. Patient should inform laboratory of any recent antibiotic therapy or urinary tract infections.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Genital tuberculosis is an important cause of infertility, especially in regions where TB is prevalent. This test helps identify Mycobacterium tuberculosis in the reproductive system, which can lead to scarring of the reproductive organs, blocked tubes, and reduced sperm quality. Early detection allows for timely treatment with anti-tuberculosis medications, potentially preserving fertility. A positive result typically requires confirmation through culture or molecular testing, and consultation with a urologist or infectious disease specialist for appropriate treatment planning.
Frequently asked questions
Why would my doctor order this test?
How long does it take to get results?
What do positive results mean?
What if my results are negative?
Can this test detect other infections?
Sources
- 1CDC - Tuberculosis (TB)Source
- 2
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 17, 2026. · Read our editorial policy