Test Overview

Test Methodology

Homogeneous Enzyme Immunoassay

Test Usage

Monitor therapeutic drug level, compliance, evaluate valproic acid toxicity

Reference Range*

2-10 mcg/mL (approximately 10% of the total drug concentration); Toxic >15 mcg/mL.

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

Test Limitations

Use of heparinized blood tubes is not allowed (may lead to artificially high free valproic acid level).

Test Details

Days Test Performed

Daily, 24 hrs

Analytic Time

2 hours

Soft Order Code


MiChart Code

Valproic Acid Level, Free



Depakene, Protein Free
Free Depakene
Free Valproic Acid

+ See More


Chemical Pathology

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Specimen Requirements

Offsite Collection Instructions

Collect blood in a red top tube. Centrifuge, aliquot serum into a plastic vial, and refrigerate.

Rejection Criteria

Heparinized samples


Yellow Top Tube

Normal Volume

1 mL serum or plasma

Minimum Volume

0.75 mL serum or plasma

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