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Lab Manual for Moffitt-Long and Mount Zion

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Giardia Antigen

Item Value
Approval req'd? No
Available Stat? No
Test code P413
Performed by Microbiology
In House Availability Thursday, day shift
Method EIA
Collection Instructions SAF tubes and instructions available from the 1st floor ACC draw station, 2330 Post St draw station, 5th floor lab at Parnassus and 2nd floor lab at MtZ.
Container type
Inpatients Clean container
ED/Outpatients SAF preservative


SAF tubes and instructions available from the 1st floor ACC draw station, 2330 Post St draw station, 5th floor lab at Parnassus and 2nd floor lab at MtZ.
Amount to Collect See preferred volume
Sample type Fresh or preserved stool
Preferred volume 10 mL
Note: fill SAF vial to red line on label
Min. Volume 5 mL
Note: fill SAF vial to red line on label
UCSF Rejection Criteria Unpreserved stool received >1 hour after collection. Stool in a preservative other than SAF. Stool not mixed well in SAF, or if preservative has been poured out. SAF container filled past the red line on the container label.
Processing notes Transfer unpreserved stool to SAF preservative upon receipt in lab.
Normal range Negative
Synonyms String test;
Stability Room temperature:
Unpreserved stool 1 hour
Stool in SAF 2 months
Turn around times 1-7 days
Additional information This test should be used only if other parasitic infections not detected by this highly specific procedure are considered unlikely on clinical grounds or have been excluded by routine stool examinations for O&P. The test can be used to follow infected patients for loss of carriage (at no more than weekly intervals), to investigate their contacts, or when-despite the failure to demonstrate it by stool examination a high suspicion of Giardia infection persists. Sensitivity of this test for parasite antigen is 96%, compared to a sensitivity of 74% for the microscopic examination of a single stool sample; specificity is thought to be 100%.

The 'String test' is no longer offered
CPT coding 87328
LOINC code 6412-1
Last Updated 6/19/2013 2:38:04 PM
Entry Number 419

If you have additional questions regarding this test, please call: 415-353-1667

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