Test Overview

Test Methodology

Chemiluminescent Assay

Test Usage

Assessment of risk for occlusive vascular disease, obstetric complications (recurrent spontaneous abortion, gross placental infarction), and neural tube defects (hyperhomocysteinemia). Patients taking methotrexate, nicotinic acid, theophylline, nitrous oxide or L-Dopa may have falsely elevated Homocysteine levels. S-adenosyl-methionine is an antidepressant that is structurally similar to S-adenohomocysteine. Individuals taking this drug may show elevated levels of Homocysteine.

Reference Range*

5 - 15 mcmol/L. The population determined reference interval for homocysteine is 5-15uM. However, studies have shown a gradual increase in risk for atherosclerosis as homocysteine levels increase above 11 uM.

* Reference ranges may change over time. Please refer to the original patient report when evaluating results.

Test Limitations

Homocysteine levels may be affected by gross hemolysis or lipemia.

Test Details

Days Test Performed

Daily, 24 hours

Analytic Time

4 hours

Soft Order Code


MiChart Code





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Chemical Pathology

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Specimen Requirements

Offsite Collection Instructions

Collect blood in a lavender top tube from a fasting patient. Centrifuge and aliquot plasma into plastic vial within 30 minutes of collection. Freeze (preferred) or refrigerate up to 2 days; specimens stored at room temperature are unacceptable.

Special Handing

Fasting specimen preferred. Place on ice immediately and deliver to lab or aliquot within 30 minutes.


Lavender Top Tube

Normal Volume

2 mL EDTA whole blood or 1 mL EDTA plasma

Minimum Volume

1 mL EDTA whole blood or 0.5 mL EDTA plasma

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