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Glial Fibrillary Acidic Protein (GFAP)
Access Labcorp Draw · Quest Diagnostics2 test optionsFrom $553.16
Glial Fibrillary Acidic Protein (GFAP)
Access Labcorp Draw · Quest DiagnosticsCatalog information reviewed: August 24, 2026 by the Sunridge Medical clinical team.
What this laboratory test evaluates
DetailsGlial Fibrillary Acidic Protein (GFAP) – Glial fibrillary acidic protein (GFAP) is a protein expressed in astrocytes, cells that support neurons and help form the blood-brain barrier, found within the central nervous system (CNS), and is involved in several important CNS processes. It is a marker of astrogliosis and is upregulated in the brain as a result of attempts at repair and the formation of a glial scar. Glial scarring occurs as a result of several neurodegenerative processes, including Alzheimer's disease, multiple sclerosis, and neuromyelitis optica. It can also be seen after damaging pathological events such as traumatic brain injury and stroke [1]. Increased presence of GFAP can also be observed in association with brain tumors such as glioblastoma multiforme [2]. GFAP expression is known to decrease in disorders such as schizophrenia, bipolar disorder, and depression [3].
1. Nature Reviews Neurology 18(3):158-172.
2. J Neuro Sci 35 (1):147-155.
3. Molecular Psychiatry 5(2):142-149.
What type of sample is required for this test?0.7 mL plasma collected in an EDTA (lavender-top) tube
Test ResourcesFor more information, please consult your healthcare provider.
Additional test information
Glial Fibrillary Acidic Protein (GFAP) – Glial fibrillary acidic protein (GFAP) is a protein expressed in astrocytes, cells that support neurons and help form the blood-brain barrier, found within the central nervous system (CNS), and is involved in several important CNS processes.
Collection and processing
- Sample type: Plasma
- Fasting: No
- Estimated laboratory processing: Results should be available in 2 – 5 business days after the sample is collected
How Sunridge uses laboratory information
Sunridge considers the medical question, symptoms, history, medications, prior results, and whether the finding could change care before recommending testing. A laboratory result is not interpreted in isolation and does not establish a diagnosis by itself.
Before requesting this test
Availability, collection requirements, eligibility, and processing estimates can change. Sunridge reviews each request and, when appropriate, creates the order through Fullscript. Follow the current instructions supplied with the approved order.
Common questions about this laboratory test
- What sample does this test require?
- The listed sample type is Plasma, Serum. Confirm current collection instructions in the approved order.
- Does this test require fasting?
- The current catalog record lists fasting as: No. Follow the instructions supplied with the approved order.
- How long does laboratory processing usually take?
- Results should be available in 2 – 5 business days after the sample is collected. Timing can change after collection or if a laboratory requires additional review.
About this test
DetailsGlial Fibrillary Acidic Protein (GFAP) - Glial fibrillary acidic protein (GFAP) is a protein expressed in astrocytes, cells that support neurons and help form the blood-brain barrier, found within the central nervous system (CNS), and is involved in several important CNS processes. It is a marker of astrogliosis and is upregulated in the brain as a result of attempts at repair and the formation of a glial scar. Glial scarring occurs as a result of several neurodegenerative processes, including Alzheimer's disease, multiple sclerosis, and neuromyelitis optica. It can also be seen after damaging pathological events such as traumatic brain injury and stroke [1]. Increased presence of GFAP can also be observed in association with brain tumors such as glioblastoma multiforme [2]. GFAP expression is known to decrease in disorders such as schizophrenia, bipolar disorder, and depression [3].
1. Nature Reviews Neurology 18(3):158-172.
2. J Neuro Sci 35 (1):147-155.
3. Molecular Psychiatry 5(2):142-149.
What type of sample is required for this test?0.7 mL plasma collected in an EDTA (lavender-top) tube
Test ResourcesFor more information, please consult your healthcare provider.
Additional details
Glial Fibrillary Acidic Protein (GFAP) - Glial fibrillary acidic protein (GFAP) is a protein expressed in astrocytes, cells that support neurons and help form the blood-brain barrier, found within the central nervous system (CNS), and is involved in several important CNS processes.
Highlighted health areas
- Neurological
Biomarkers and report focus
The exact analytes and report format can change. Confirm the current contents in the Fullscript order before payment.
- Glial Fibrillary Acidic Protein (GFAP)