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Test Code Tryptase Tryptase, Serum

Reporting Name

Tryptase, S

Useful For

Assessing mast cell activation, which may occur as a result of anaphylaxis or allergen challenge


Assessing patients with systemic mastocytosis or mast cell activation syndrome

Specimen Required


Preferred: Serum gel

Acceptable: Red top

Specimen Volume: 0.5 mL

Seattle Children's Hospital Note:

Collect 1.0 mL whole blood in a red top.

Specimen Type


Specimen Minimum Volume

0.2 mL

Specimen Stability Information

Specimen Type Temperature Time
Serum Frozen (preferred) 14 days
  Refrigerated  14 days

Day(s) and Time(s) Performed

Monday through Friday; 9 a.m. and 1 p.m.

Performing Laboratory

Mayo Medical Laboratories in Rochester

Method Name

Fluorescence Enzyme Immunoassay (FEIA)

Method Description

Anti-tryptase, covalently coupled to ImmunoCAP, reacts with tryptase in the patient serum specimen. After washing, enzyme-labeled antibodies against tryptase are added to form a complex. After incubation, unbound enzyme-labeled antibodies are washed away and the bound complex is incubated with a developing agent. After stopping the reaction, the fluorescence in the eluate is measured. The fluorescence is directly proportional to the concentration of tryptase in the serum specimen.(Package insert: ImmunoCAP Tryptase, Phadia AB, Uppsala, Sweden)

Reference Values

<11.5 ng/mL

Test Classification

This test has been cleared or approved by the U.S. Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.

CPT Code Information


LOINC Code Information

Test ID Test Order Name Order LOINC Value
TRYPT Tryptase, S 21582-2


Result ID Test Result Name Result LOINC Value
TRYPT Tryptase, S 21582-2

Reject Due To


Mild OK; Gross OK


Mild OK; Gross OK


Mild OK; Gross OK




If not ordering electronically, complete, print, and send a General Request Form (T239) with the specimen (