Skip to content

Tryptase Beta-1 Activity, Whole Blood

Published: August 9, 2026Updated: August 16, 2026

Measures beta-1 tryptase activity in whole blood to help evaluate mast-cell activation and disorders such as systemic mastocytosis.

Quick summary

["This blood test can help identify increased mast-cell activity, but results must be interpreted with symptoms and other findings."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
107445-9
Short code
TPSAB1 EntNum Bld/T
Synonyms
TPSAB1 EntNum Bld/T
Category
tumor-marker
Sample
whole-blood
Container
Lavender-top (EDTA)
Units
N/A
Ref low
0
Ref high
4
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
molgen
CPT
84153
SNOMED
39392002
Specimen volume
3 mL
Stability
Room temperature: 4h, Refrigerated: 24h
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

What is this test?

Tryptase is an enzyme released by mast cells, which are immune cells involved in allergic and inflammatory responses. This test measures the activity of the beta-1 form of tryptase in a whole-blood sample.

Why might I need this test?

A clinician may order this test when symptoms suggest excessive mast-cell activation, such as recurrent episodes of hives, flushing, swelling, abdominal symptoms, or unexplained anaphylaxis. It may also be used when evaluating a possible systemic mast-cell disorder.

How is the test performed?

A blood sample is collected by venipuncture and analyzed in the laboratory to determine beta-1 tryptase activity. Because tryptase can fluctuate, the result should be compared with symptoms, the timing of any reaction, and other laboratory findings.

How do I prepare for the test?

No special preparation or fasting is usually required. Tell your clinician about any recent allergic reaction, anaphylaxis, infection, or other major health event, because these factors can affect how the result is interpreted.

Reference range

Normal: <4.0 ng/mLN/A

Specimen: whole-blood

No special preparation required. For PSA, avoid sexual activity for 24-48 hours before the test.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Beta-1 Tryptase

Frequently asked questions

What does beta-1 tryptase measure?
It measures the activity of beta-1 tryptase, an enzyme associated with mast cells in whole blood. Higher activity can suggest increased release of mast-cell enzymes.
Is this the same as a total tryptase test?
No. This test specifically evaluates the beta-1 form, while a total tryptase test measures several forms together. A clinician may use one or both depending on the situation.
Does an elevated result mean I have mast cell disease?
Not necessarily. Elevated activity may occur during a severe allergic reaction or other periods of mast-cell activation and must be considered along with your symptoms and other test results.
  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 16, 2026. · Read our editorial policy