Understanding Your Laboratory Test: From Sample Collection to Results
A laboratory test that identifies bacteria present in corneal samples to diagnose eye infections.
{"This test detects and identifies bacteria causing corneal infections","A small sample is collected from the cornea using a sterile technique","Results help doctors select the most effective antibiotic treatment"}
Key facts at a glance
- LOINC
- 60257-3
- Short code
- CORCULT
- Synonyms
- Bacteria Crn Cult
- Category
- chemistry
- Sample
- serum
- Container
- Sterile transport swab in Amies or Stuart transport medium; sterile screw-cap container for corneal scrapings or biopsy tissue; inoculate directly onto culture media at bedside when possible
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 0–120 years
- Method
- culture
- CPT
- 87070
- SNOMED
- 385723002
- Specimen volume
- Corneal scraping or swab specimen; minimum quantity sufficient to inoculate culture media plates
- Stability
- Transport to laboratory within 2 hours at room temperature. If immediate transport is not possible, specimen in Amies transport medium is stable at room temperature (20-25°C) for up to 24 hours. Corneal biopsy tissue should be processed promptly.
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 48–240 hours
- Order
- routine
This laboratory test analyzes a sample of your blood, urine, or other body fluid to measure specific substances and help your doctor evaluate your overall health, diagnose a medical condition, or monitor how well a treatment is working over time.
The Corneal Bacterial Culture test is a laboratory procedure that identifies specific bacteria present in a sample taken from your cornea. When your eye doctor suspects a corneal infection (keratitis), they collect a small sample of tissue, fluid, or discharge from the cornea and send it to a laboratory for analysis. The lab grows (cultures) the bacteria to determine exactly what type is causing the infection.
A trained healthcare professional will collect your sample, usually by drawing a small amount of blood from a vein in your arm using a fine needle, or by asking you to provide a urine or swab specimen in a sterile container, depending on what your test requires.
Your eye doctor will use a sterile instrument to gently scrape or collect a small sample from the infected area of your cornea. Before the procedure, numbing eye drops are applied to minimize discomfort. The collection process takes only a few seconds. The sample is then placed in a sterile container and sent to a microbiology laboratory for culture and analysis.
Once your sample arrives at the laboratory, trained laboratory professionals prepare and analyze it using specialized instruments and quality-controlled methods, and a laboratory scientist verifies each result carefully before it is released to your healthcare provider.
In the lab, the sample is placed onto special growth media and incubated at body temperature. If bacteria are present, they will multiply over several days. Laboratory technicians then identify the specific type of bacteria and perform antibiotic sensitivity testing (susceptibility testing) to determine which antibiotics will effectively treat the infection.
Most routine test results are ready within one to three business days, although some specialized tests may take a week or longer; your healthcare provider will contact you to review your results and explain what they mean for your care.
Preliminary results may be available in 2-3 days, but complete results, including antibiotic sensitivity, typically take 5-7 days. Some slow-growing bacteria may require longer incubation. Your doctor will start treatment based on clinical symptoms while waiting for final results.
Reference range
No growth of pathogenic bacteria isolated. Normal ocular flora (e.g., coagulase-negative staphylococci) may be reported as part of the resident microbiome.N/A
Patient should not have topical antibiotics instilled for at least 24 hours prior to specimen collection whenever clinically feasible. Contact lenses should be removed prior to sampling. Avoid touching the cornea or eyelashes during collection to minimize contamination.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Corneal bacterial culture is essential for diagnosing infectious keratitis, a serious condition that can threaten vision if left untreated. Common causative bacteria include Staphylococcus aureus, Streptococcus species, Pseudomonas aeruginosa (especially in contact lens wearers), and Enterobacteriaceae. Accurate identification allows for targeted antibiotic therapy, improving outcomes and reducing complications such as corneal scarring or vision loss. This test is particularly important when initial antibiotic treatment fails or when the infection is severe.
Frequently asked questions
Is the sample collection painful?
Can I wear contact lenses during treatment?
What if the culture shows no growth?
How is the treatment adjusted based on culture results?
Sources
- 1
- 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 16, 2026. · Read our editorial policy