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Total Antioxidant Capacity of Plasma (ORAC-like Method)

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

This test measures how effectively your blood plasma resists oxidative damage, which helps protect cells from harmful free radicals.

Quick summary

["Your blood’s natural antioxidant defenses may be assessed to support overall health and disease prevention."]

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

Key facts at a glance

LOINC
49448-4
Short code
T gondii DNA # Spec NAA+probe
Synonyms
T gondii DNA # Spec NAA+probe
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
probe-amp-tar
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

What Does This Test Measure?

This test evaluates the total antioxidant capacity of your plasma, which reflects the combined ability of various antioxidants (such as vitamins, enzymes, and polyphenols) to neutralize free radicals. Free radicals are unstable molecules that can cause cellular damage if left unchecked, potentially contributing to chronic conditions like heart disease or aging.

Why Might You Need This Test?

Healthcare providers may order this test to assess oxidative stress, evaluate antioxidant status in conditions like metabolic syndrome, diabetes, or chronic inflammation, or monitor responses to antioxidant supplements.

How Is the Test Performed?

A blood sample is drawn from a vein, typically in the arm. The plasma portion is then analyzed using a specialized probe-based method to measure its ability to neutralize free radicals over time.

What Does a Result Mean?

Results indicate the overall capacity of your plasma to neutralize oxidative stress. Lower than expected levels may suggest increased oxidative damage or reduced antioxidant defenses, while higher levels may indicate stronger protective mechanisms.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

Plasma Antioxidant Capacity

Frequently asked questions

How often will I need this test?
This test is not routinely recommended for most people, as it is primarily used in research or specialized clinical settings to assess antioxidant status in specific conditions. Your doctor may suggest it if they suspect oxidative stress or are evaluating antioxidant therapy.
What are the normal ranges for this test?
No standard reference ranges are widely established for this test due to its specialized methodology. Results are typically interpreted relative to clinical context rather than absolute values.
Can I prepare for this test in any way?
No special preparation is needed. However, avoid heavy exercise or consuming large amounts of antioxidant-rich foods (e.g., fruits, nuts) 24 hours before the test, as they may temporarily alter 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