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Test Code VALPX or LAB24 Valproic Acid Level, Serum or Plasma

Important Note

For information on draw times, please call Bronson lab client services at 269-341-6440.

For general guidelines on therapeutic drug monitoring (TDM), please see the TDM general guidelines document. 

Specimen Requirements

Container Type:

Optimal: Gold or Mint*

*For STAT requests

Acceptable: Red or Green
Optimal Collection Volume: 

4.5mL; full tube
Minimum Volume:
  • Adults: 1 mL whole blood
  • Neonates: 1 microtainer (400-600 uL)
Collection Instructions:

Gently invert the sample 5-6 times after collection.
Specimen Transport:

Refrigerate
Processing Instructions: 

1. If serum, allow the specimen to clot for 30 minutes.

2. Centrifuge specimen within 2 hours of collection.

3. After centrifugation, specimen tubes without a gel barrier should have the serum or plasma aliquoted to a false bottom container.

4. Keep the serum or plasma refrigerated until testing can be performed.

Specimen Stability

Specimen Type Temperature Time
Serum* Refrigerated 7 days
Room Temperature 2 days
Frozen 3 months

*Note: Heparinized plasma in gel separator tubes is less stable than serum and is only suitable for add-on testing up to 2 days following sample collection.

Specimen Rejection Criteria

Hemolysis Mild OK; Moderate OK; Gross Reject
Lipemia Mild OK; Moderate OK; Gross Reject
Icterus Mild OK; Moderate OK; Gross Reject
Other Quantity not sufficient

Useful For

Monitoring therapeutic concentrations of Valproic acid.

Methodology

Roche Cobas - Homogeneous enzyme immunoassay

Reference Ranges

Therapeutic range: 50-100 ug/mL

 

Critical Value: > 200 ug/mL

Interpretive

VALPA - Clinical & Interpretive: Valproic Acid, Total, Serum (mayocliniclabs.com)

Day(s) Performed

24/7

Expected TAT

Same day

Performing Laboratory

Bronson Laboratory, Chemistry - Kalamazoo, Battle Creek, Paw Paw, South Haven

Sample Retention Time

7 days

CPT Code

80164

LOINC Code

4086-5