Skip to content

Yeast, Bronchial Specimen — KOH Preparation, Qualitative

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

A qualitative microscopy test that checks a bronchial specimen for yeast or other fungal forms after preparation with potassium hydroxide.

Quick summary

["Detecting yeast in a bronchial specimen may indicate fungal colonization or infection, but the result must be interpreted with symptoms and other tests."]

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

Key facts at a glance

LOINC
55320-6
Short code
Yeast Bronch Ql KOH Prep
Synonyms
Yeast Bronch 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 bronchial specimen for yeast using a potassium hydroxide (KOH) preparation. KOH helps clear cellular material so fungal forms can be seen under a microscope.

Why might I need this test?

It may be used when a lung infection is suspected, especially in people with respiratory symptoms, weakened immune systems, or imaging findings that may suggest fungal disease.

How is the test performed?

A clinician collects lower-respiratory material, often during bronchoscopy. A laboratory prepares the specimen with KOH and examines it microscopically for yeast and other fungal forms.

How do I prepare for the test?

Follow the instructions provided for collection. If bronchoscopy is being performed, your care team will give you specific preparation instructions, including any fasting or medication guidance.

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

Bronchial yeast KOH preparation

Frequently asked questions

What does a positive yeast result mean?
Yeast was detected in the bronchial specimen, but this does not by itself prove that yeast is causing an infection. Your clinician will interpret it alongside your symptoms and other test results.
Can this test identify the type of yeast?
Usually not. A culture or other fungal testing may be needed to identify the organism more precisely.
How is a KOH preparation different from a fungal culture?
A KOH preparation provides a rapid microscopic look for fungal forms. A culture takes longer but can identify the organism and may help guide treatment.
  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