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Fluorescent Immunoassay for Granulocyte Count (Absolute Neutrophil Count)

Published: August 9, 2026Updated: August 17, 2026

This test measures the number of neutrophils, a type of white blood cell, in your blood. Neutrophils help fight infections and inflammation.

Quick summary

["Understanding your neutrophil count helps doctors check for infections, immune issues, or blood disorders."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 17, 2026Editorial policy

Key facts at a glance

LOINC
102741-6
Short code
Flounder IgG RAST
Synonyms
Flounder IgG RAST
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Ref low
10
Ref high
40
Critical range
— – 500 N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
rast
CPT
84484
SNOMED
302774002
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

Why This Test Is Done

Doctors may order this test to diagnose or monitor conditions like infections (e.g., bacterial infections), certain blood disorders (e.g., leukemia), or immune system problems. It can also help evaluate responses to treatments.

What to Expect Before the Test

No special preparation is needed. You may have a small needle inserted into your arm to draw blood, which usually takes a few minutes. If you’re on blood thinners, let your doctor know before the test.

What the Test Results Mean

Results are typically reported as a count of neutrophils per microliter (µL) of blood. Low counts may indicate infections, immune disorders, or bone marrow problems, while very high counts could signal inflammation or other conditions.

Common Conditions Affecting Neutrophil Count

Conditions like chronic infections, autoimmune diseases, or certain cancers can alter neutrophil levels. Your doctor will interpret results in the context of your overall health and symptoms.

Reference range

Adult: 10-40 U/LN/A

Specimen: serum

No special preparation required. Avoid fatty meals before the test if possible.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Neutrophil Count (FIA)

Frequently asked questions

What causes a low neutrophil count?
Low neutrophil counts can result from infections, certain medications, autoimmune diseases, or bone marrow disorders. If you notice frequent infections or fatigue, discuss symptoms with your doctor.
What causes a high neutrophil count?
High neutrophil counts often appear during infections, inflammation, or stress. Chronic conditions like rheumatoid arthritis or certain cancers may also elevate these cells. Your doctor will review your medical history.
Can diet or lifestyle affect neutrophil counts?
While diet and lifestyle factors like stress or sleep may influence immune function indirectly, they don’t directly alter neutrophil counts. Focus on maintaining good health habits to support overall immune function.
  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 17, 2026. · Read our editorial policy