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HelpCatalog ID FLUC 5-Flucytosine, Serum
Reporting Name
5-Flucytosine, SUseful For
Monitoring serum concentration during therapy
Evaluating potential toxicity
May aid in evaluating patient compliance
Specimen Required
Supplies: Sarstedt Aliquot Tube, 5 mL (T914)
Collection Container/Tube:
Preferred: Red top
Acceptable: Serum gel
Submission Container/Tube: Plastic vial
Specimen Volume: 0.5 mL
Collection Instructions:
1. Serum for a peak level should be collected 1 to 2 hours after oral dose or 30 minutes after intravenous infusion. Trough specimens should be collected immediately prior to next scheduled dose.
2. Within 2 hours of collection, centrifuge, and aliquot serum to plastic vial.
Collect 1.2 mL blood in Red top tube.
Reference Values
Therapeutic concentration:
Peak >25.0 mcg/mL (difficult infections may require higher concentrations)
Toxic concentration:
Peak >100.0 mcg/mL
Day(s) Performed
Tuesday, Thursday
Reject Due To
| Gross hemolysis | OK |
| Gross lipemia | OK |
| Gross icterus | OK |
Specimen Type
SerumSpecimen Minimum Volume
0.3 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Serum | Refrigerated (preferred) | 28 days | |
| Ambient | 28 days | ||
| Frozen | 28 days |
Test Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.Performing Laboratory
Mayo Clinic Laboratories in Rochester
CPT Code Information
80299
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| FLUC | 5-Flucytosine, S | 3639-2 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 82741 | 5-Flucytosine, S | 3639-2 |
Method Name
Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
Secondary ID
82741Forms
If not ordering electronically, complete, print, and send a Therapeutics Test Request (T831) with the specimen.