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Granulocyte Colony-Stimulating Factor (G-CSF) Level, Serum or Plasma

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

This test measures the level of granulocyte colony-stimulating factor (G-CSF) in your blood. G-CSF is a protein that helps stimulate the production of white blood cells, particularly neutrophils, which are important for fighting infections.

Quick summary

["G-CSF helps your body produce more white blood cells to support immune function."]

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

Key facts at a glance

LOINC
102810-9
Short code
Safflower IgG RAST
Synonyms
Safflower 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 Is This Test Done?

Your healthcare provider may order this test to monitor your response to G-CSF therapy, assess bone marrow function, or evaluate conditions affecting white blood cell production, such as chemotherapy side effects, infections, or certain blood disorders.

What to Expect Before the Test

No special preparation is usually needed. You may have a small needle inserted into a vein in your arm or hand to draw a blood sample. If you’re on G-CSF therapy, your levels may be checked regularly to ensure it’s working properly.

What the Test Results Mean

Higher-than-normal levels might indicate overstimulation of white blood cell production, while lower-than-normal levels could suggest insufficient production or a problem with your bone marrow.

Common Conditions Monitored

This test is often used in patients undergoing chemotherapy, those with low white blood cell counts (neutropenia), or those receiving treatments like G-CSF itself to boost immune support.

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.

Clinical Significance: G-CSF Levels Help Guide Treatment Adjustments

Short name

G-CSF Level

Frequently asked questions

How often will I need this test?
Your provider will determine the frequency based on your treatment plan, but it may be done weekly or monthly during active therapy.
What do my results mean if they’re outside the normal range?
If results are low, it may signal a need for a different treatment approach or further investigation into bone marrow function. If high, it could indicate an overactive immune response or side effects from therapy.
Can I eat or drink before this test?
You can eat and drink normally unless your provider specifies otherwise. Blood tests typically don’t require fasting unless measuring substances like glucose or lipids.
  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