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: Fungal Culture and Potassium Hydroxide (KOH) Preparation, Specimen

Published: August 9, 2026Updated: August 16, 2026

: This test combines a direct microscopic examination of a specimen treated with potassium hydroxide (KOH) with a fungal culture to detect and identify fungal organisms.

Quick summary

[": A KOH preparation and fungal culture together help determine whether a specimen contains fungi and, if so, which organism is present."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
55304-0
Short code
Fungus Spt Ql KOH Prep
Synonyms
Fungus Spt Ql KOH Prep
Category
chemistry
Sample
sputum
Container
Sterile sputum container
Units
N/A
Ref low
0.8
Ref high
1.2
Critical range
— – 5 N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
koh-preparation
CPT
85610
SNOMED
396252006
Specimen volume
3-5 mL
Stability
Room temperature: 2h, Refrigerated: 24h
TAT
4–24 hours
Order
routine

: What This Test Does

: The test looks for fungi in a sample taken from a body site. A KOH preparation dissolves non-fungal material so fungi can be seen directly under a microscope, while a culture gives organisms a chance to grow so they can be identified.

: How the Sample Is Collected

: A healthcare provider collects the specimen, which may be skin scrapings, nail clippings, hair, or another sample depending on the suspected infection. The sample is then sent to the laboratory for microscopic review and culture.

: What the Results Mean

: A positive KOH preparation or culture suggests fungal elements are present. A negative result does not always rule out infection, and results are interpreted together with symptoms, the sampling site, and other findings.

: Why the Method Matters

: The KOH preparation offers a rapid direct look for fungi, while culture supports confirmation and identification of the organism. Using both approaches can improve detection and help guide treatment decisions.

Reference range

INR: 0.8-1.2 (warfarin: 2.0-3.0)N/A

Specimen: sputum

Inform your healthcare provider if you are taking blood thinners. No special preparation required.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

: Fungal Smear and Culture

Frequently asked questions

: Does a positive result always mean I have an infection?
: Not necessarily. Some fungi can be present without causing disease, so a positive result is interpreted along with symptoms, the collection site, and other clinical information.
: How long does the culture take?
: Culture times vary by organism and laboratory, and some fungi grow slowly. Your provider or laboratory can give the expected turnaround for your specific sample.
: Can I get results from the KOH preparation sooner than the culture?
: The KOH preparation is typically reviewed soon after the sample reaches the laboratory, while culture results usually take longer because organisms need time to grow.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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