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Test Code INSFTM Insulin, Free and Total, Serum

Additional Codes



Useful For

Assessing free (bioactive) insulin concentrations in patients with known or suspected insulin antibodies

Profile Information

Test ID Reporting Name Available Separately Always Performed
INSF Insulin, Free, S No Yes
INSTO Insulin, Total, S Yes, (Order as INS) Yes

Method Name

Electrochemiluminescence Immunoassay (ECLIA)

Reporting Name

Insulin, Free and Total, S

Specimen Type


Specimen Required

Patient Preparation:

1. Fasting (8 hours)

2. For 12 hours before specimen collection do not take multivitamins or dietary supplements containing biotin (vitamin B7), which is commonly found in hair, skin, and nail supplements and multivitamins.

Collection Container/Tube:

Preferred: Serum gel

Acceptable: Red top

Submission Container/Tube: Plastic vial

Specimen Volume: 1 mL

Collection Instructions:

1. Avoid hemolysis

2. Label specimens with corresponding draw times.

3. Serum-gel tubes should be centrifuged within 2 hours of collection.

4. Red-top tubes should be centrifuged and aliquoted within 2 hours of collection.

5. Send specimen refrigerated

Additional Information: If multiple specimens are drawn, send separate order for each specimen.

Specimen Minimum Volume

0.75 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Serum Refrigerated (preferred) 14 days
  Frozen  180 days
  Ambient  24 hours

Reject Due To

Gross hemolysis Reject
Gross lipemia OK
Autopsy/postmortem specimen Reject

Reference Values


2.6-24.9 mcIU/mL



2.6-24.9 mcIU/mL

Day(s) Performed

Monday through Thursday

Report Available

1 to 4 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

This test has been modified from the manufacturer's instructions. Its performance characteristics were determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information

83527-Free Insulin

83525-Total Insulin

LOINC Code Information

Test ID Test Order Name Order LOINC Value
INSFT Insulin, Free and Total, S 48615-9


Result ID Test Result Name Result LOINC Value
INSTO Insulin, Total, S 20448-7
INSF Insulin, Free, S 6901-3

Secondary ID