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Test Code INSFT Insulin, Free and Total, Serum

Important Note

OrderGO23910 Generic Orderable/Misc Test 

Useful For

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

 

Profile Information

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

Method Name

Electrochemiluminescence Immunoassay (ECLIA)

Reporting Name

Insulin, Free and Total, S

Specimen Type

Serum


Specimen Required


Patient Preparation:

1. Fasting: 8 hours, required

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: 2.45 mL

Collection Instructions:

1. Avoid hemolysis

2. Label specimens with corresponding collection 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 collected, send separate order for each specimen.


Specimen Minimum Volume

0.75 mL

Specimen Stability Information

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

Reject Due To

Gross hemolysis Reject
Gross lipemia OK
Gross icterus OK
Autopsy/postmortem specimen Reject

Reference Values

FREE INSULIN:

3-25 mcIU/mL

 

TOTAL INSULIN:

3-25 mcIU/mL

Cautions

In rare cases, some individuals can develop antibodies to mouse or other animal antibodies (often referred to as human anti-mouse antibodies [HAMA] or heterophile antibodies), which may cause interference in some immunoassays. The presence of antibodies to streptavidin or ruthenium can also rarely occur and may also interfere in this assay. Caution should be used in interpretation of results, and the laboratory should be alerted if the result does not correlate with the clinical presentation.

 

Hemolysis interferes with this assay, as insulin-degrading peptidases are released from erythrocytes.This assay has 100% cross-reactivity with recombinant human insulin (Novolin R and Novolin N). It does not recognize other commonly used analogues of injectable insulin (ie, insulin lispro, insulin aspart, and insulin glargine).

Day(s) Performed

Monday, Wednesday, Friday

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

NY State Approved

Yes

Secondary ID

62990