Nonesterified Fatty Acids (Free Fatty Acids)

Free Fatty Acids, Total, Serum

Test Codes

EPIC: LAB1232163, Beaker: FreeFattyTot, Quest: 449

Department

Send Outs

Instructions

Overnight fasting is preferred.

Specimen Collection Criteria

Collect (preferred specimen): One Gold-top SST tube.

Also acceptable: One plain Red-top tube.

Physician Office/Draw Specimen Preparation

Critical frozen. Let specimen clot then centrifuge to separate serum from cells with 45 minutes of collection. Transfer serum to a plastic transport tube and freeze (-20°C/-4°F or below) immediately.

Preparation for Courier Transport

Transport: 1.0 mL serum, frozen (-20°C/-4°F or below). (Minimum: 0.3 mL)

Rejection Criteria

• Received thawed.
• Received refrigerated.
• Heparin plasma.
• Patients on heparin therapy.
• Specimens not collected and processed as indicated.

Inpatient Specimen Preparation

Critical frozen. Transport specimen to the Laboratory immediately after collection, on ice, for processing.

In-Lab Processing

Critical frozen. Let specimen clot then centrifuge to separate serum from cells with 45 minutes of collection. Transfer serum to a plastic transport tube and freeze (-20°C/-4°F or below) immediately.

Transport: 1.0 mL serum, frozen (-20°C/-4°F or below). (Minimum: 0.3 mL)

Storage

Specimen Stability for Testing:

Room Temperature (20-26°C or 68-78.8°F): Unacceptable
Refrigerated (2-8°C or 36-46°F): 2 hours
Frozen (-20°C/-4°F or below): 30 days

Specimen Storage in Department Prior to Disposal:

Specimen retention time is determined by the policy of the reference laboratory. Contact the Send Outs Laboratory with any questions.

Laboratory

Sent to Quest Diagnostics, Wood Dale, IL.

Performed

Tuesday, Thursday.
Results available in 3-8 days.

Reference Range

Newborns	<2.3 mmol/L
1-12 Months	0.50-1.60 mmol/L
1-7 Years	0.60-1.50 mmol/L
8-17 Years	0.20-1.10 mmol/L
Adults	0.07-0.88 mmol/L

Test Methodology

Spectrophotometry (SP), Enzymatic

Interpretation

By report.

Clinical Utility

Nonesterified Fatty Acids (Free Fatty Acids) – The Nonesterified Fatty Acids (Free Fatty Acids) assay is useful in evaluating lipolysis and fatty acid oxidation. Nonesterified Fatty Acids may be useful in evaluating patients with hypoglycemia.

CPT Codes

82725

Contacts

Last Updated

12/19/2025