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22650 Fungus, Direct Wet Prep

Fungus, Direct Wet Prep
Test Code: KOHFS
Synonyms/Keywords
KOH Smear, Calcofluor white smear, fungal, fungus
Useful For
​Presumptive diagnosis of fungal elements in direct specimens.
Specimen Requirements
Fasting Required Specimen Type Preferred Container/Tube Acceptable Container/Tube Specimen Volume Specimen Minimum Volume
(allows for 1 repeat)		 Pediatric Minimum Volume
(no repeat)
No​
Any
(except blood and bone marrow)​
 Sterile leakproof container Wet prep tube (1.0 mL sterile 0.85% saline)

 

1-10 mL
1-10 g
1-3 nails or skin scrapings

 

1 swab​
1 mL
1 g
1 nail
 
Skin scrapings

1 swab
1 mL
1 g
1 nail

 

Skin scrapings

 

1 swab

 

Collection Processing Instructions
A fungus wet prep is routinely performed on respiratory specimens and pleural fluids submitted on fungus culture.  Only order this test if a fungus wet prep is desired and:

- A non-respiratory specimen is also being submitted for fungus culture.
- A fungus culture is not being ordered.
 
Specimens should be collected in sterile leakproof containers without preservatives.  Swab-collected specimens and fecal specimens are NOT recommended. One swab in a wet prep tube (1.0 mL 0.85% saline- Inventory Item #563725) may be submitted from urogenital or oral sources only. Moisten small pieces of tissue with several drops of sterile, non-bacteriostatic normal saline.
 
For nail and skin samples, see Culture, Fungus-Dermal (FSKIN).
 
For blood and bone marrow FUNG culture, see CULTURE, Fungus-Blood (FBLD).
Specimen Stability Information
Specimen Type Temperature Time
CSF​ Room Temperature​ <72 hours​
All other specimen types​ Room Temperature​ < = 4 hours
Refrigerate​ > 4 hours
Rejection Criteria
Dried swabs or tissues
Specimens submitted in formalin or other preservatives​
​Leaking specimens
​Specimens older than 4 days
​Specimens submitted in Eswabs
Performing Laboratory Information

Performing Location Day(s) Test Performed Analytical Time Methodology/Instrumentation
​Marshfield Monday through Friday ​1 day KOH/Calcofluor Stain/Microscopy
Test Information
Microscopic examinations are less sensitive than culture for fungi and do not yield information concerning the viability of observed organisms.
 
The fungal load in a clinical specimen may be low. Specimens with less than the recommended volumes may therefore lead to a false negative result.
Reference Range Information
Performing Location Reference Range
All Performing Sites No fungal elements observed​
​ See Critical Value List for list of current critical values.​
Outreach CPTs
CPT Modifier
(if needed)		 Quantity Description Comments
87206​ ​ ​ Calcofluor​ ​
87220​ ​ ​ KOH (Potassium Hydroxide)​ ​
Synonyms/Keywords
KOH Smear, Calcofluor white smear, fungal, fungus
Ordering Applications
Ordering Application Description
​Cerner ​KOH Smear (Non-urogenital)

If the ordering application you are looking for is not listed, contact your local laboratory for assistance.
Specimen Requirements
Fasting Required Specimen Type Preferred Container/Tube Acceptable Container/Tube Specimen Volume Specimen Minimum Volume
(allows for 1 repeat)		 Pediatric Minimum Volume
(no repeat)
No​
Any
(except blood and bone marrow)​
 Sterile leakproof container Wet prep tube (1.0 mL sterile 0.85% saline)

 

1-10 mL
1-10 g
1-3 nails or skin scrapings

 

1 swab​
1 mL
1 g
1 nail
 
Skin scrapings

1 swab
1 mL
1 g
1 nail

 

Skin scrapings

 

1 swab

 

Collection Processing
A fungus wet prep is routinely performed on respiratory specimens and pleural fluids submitted on fungus culture.  Only order this test if a fungus wet prep is desired and:

- A non-respiratory specimen is also being submitted for fungus culture.
- A fungus culture is not being ordered.
 
Specimens should be collected in sterile leakproof containers without preservatives.  Swab-collected specimens and fecal specimens are NOT recommended. One swab in a wet prep tube (1.0 mL 0.85% saline- Inventory Item #563725) may be submitted from urogenital or oral sources only. Moisten small pieces of tissue with several drops of sterile, non-bacteriostatic normal saline.
 
For nail and skin samples, see Culture, Fungus-Dermal (FSKIN).
 
For blood and bone marrow FUNG culture, see CULTURE, Fungus-Blood (FBLD).
Specimen Stability Information
Specimen Type Temperature Time
CSF​ Room Temperature​ <72 hours​
All other specimen types​ Room Temperature​ < = 4 hours
Refrigerate​ > 4 hours
Rejection Criteria
Dried swabs or tissues
Specimens submitted in formalin or other preservatives​
​Leaking specimens
​Specimens older than 4 days
​Specimens submitted in Eswabs
Useful For
​Presumptive diagnosis of fungal elements in direct specimens.
Reference Range Information
Performing Location Reference Range
All Performing Sites No fungal elements observed​
​ See Critical Value List for list of current critical values.​
For more information visit:
Performing Laboratory Information

Performing Location Day(s) Test Performed Analytical Time Methodology/Instrumentation
​Marshfield Monday through Friday ​1 day KOH/Calcofluor Stain/Microscopy
For billing questions, see Contacts
Outreach CPTs
CPT Modifier
(if needed)		 Quantity Description Comments
87206​ ​ ​ Calcofluor​ ​
87220​ ​ ​ KOH (Potassium Hydroxide)​ ​
For most current information refer to the Marshfield Laboratory online reference manual.