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Fungal Elements (Yeast and Hyphae), Qualitative — Potassium Hydroxide Preparation

Published: August 9, 2026Updated: August 17, 2026

A microscopic examination of a specimen for yeast and fungal hyphae, using a potassium hydroxide (KOH) preparation.

Quick summary

["Finding yeast or hyphae can support the presence of a fungal infection."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 17, 2026Editorial policy

Key facts at a glance

LOINC
70125-0
Short code
Yeast Hyphae Spec Ql KOH Prep
Synonyms
Yeast Hyphae Spec Ql KOH Prep
Category
liver
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Ref low
10
Ref high
40
Critical range
— – 500 N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
koh-preparation
CPT
84484
SNOMED
302774002
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

What is this test?

This test examines a specimen under a microscope for yeast and fungal hyphae, which are branching filament-like structures. A potassium hydroxide (KOH) preparation helps clear away cellular material so fungal elements may be easier to see.

Why might I need this test?

A clinician may order this test when symptoms suggest a fungal infection, such as a persistent rash, scaling, nail changes, or another unexplained infection. It can also help distinguish fungal infection from conditions that may look similar.

How is the test performed?

A small sample is collected from the area being evaluated and mixed with KOH. The laboratory then examines the preparation under a microscope and reports whether yeast or hyphae are observed.

How do I prepare for the test?

Follow the clinician's or laboratory's collection instructions. Do not clean, treat, or apply antifungal products to the area shortly before the specimen is collected unless specifically directed to do so.

Reference range

Adult: 10-40 U/LN/A

Specimen: serum

No special preparation required. Avoid fatty meals before the test if possible.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

KOH fungal preparation

Frequently asked questions

Does a positive result mean I have a fungal infection?
It may. Finding yeast or hyphae supports fungal infection, but the result is interpreted with your symptoms and other clinical findings.
What does KOH mean?
KOH stands for potassium hydroxide. It is used in a specimen preparation to help make fungal structures visible under a microscope.
Can this test identify the exact type of fungus?
Usually not. A KOH preparation generally shows whether fungal elements are present; culture or other laboratory methods may be needed to identify the organism.
  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 17, 2026. · Read our editorial policy