Insulin, Total

Label Mnemonic:	INSLT
Epic code:	LAB7389
Order form:	Laboratory Requisition
Supply order:	Supply Order Form
Billing:	Billing Policies
CPT code:	83525

Specimen(s):

Plasma

Collection Medium:

Plasma Separator Tube 4.5 mL

Alternate Collection Media:

Call laboratory for additional acceptable specimen collection containers.

Minimum:

3 mL whole blood from light green top tubes or TWO Microtainer^® devices from a fasting patient.

Turn Around Time:

1 hour (upon receipt in laboratory)

Reference Range:

2.6 - 24.9 μU/mL (fasting)

Comments:

This assay may be significantly impacted by high-dose biotin (>5 mg dose) taken within previous 12 hours. High concentrations of biotin may lead to falsely decreased results. These concentrations may be found in patients taking over-the-counter supplements with biotin content much higher than nutritional requirements for biotin. Specimens should not be collected until at least 12 hours after the last dose.

Fasting for at least 8 hours prior to collection is recommended.

This assay has 100% cross-reactivity with endogenous insulin and recombinant human insulin (e.g., Novolin R and Novolin N). It does not recognize the insulin analogs lispro (Humalog), aspart (NovoLog), and glargine (Lantus).

For additional services, contact UIDL Client Services 1-866-844- 2522.

Test Limitations:

The assay is unaffected by icterus (bilirubin is less than 90 
mg/dL), lipemia (Intralipid is less than 1800 mg/dL) and biotin is 
less than 60 ng/mL (criterion: recovery within plus or minus 10% of 
initial value). Hemolysis is less than 60 mg/dL.

Samples from patients treated with bovine or porcine insulin sometimes 
contain anti-insulin antibodies which can affect the test results.(1-2)

As with all tests containing monoclonal mouse antibodies, erroneous 
findings may be obtained from samples taken from patients who have 
been treated with monoclonal mouse antibodies or have received them 
for diagnostic purposes. Elecsys Insulin contains additives which 
minimize these effects. In rare cases, interference due to extremely 
high titers of antibodies to streptavidin can occur.

For diagnostic purposes, Insulin findings should always be assessed in 
conjunction with the patient's medical history, clinical examination 
and other findings.

(1) Fiedler, H. Basiswissen Labordiagnostik: Diabetes mellitus und
    metabolisches Syndrom. Roche Diagnostics Brochure 1999;14,67 Cat
    No. 1951769.

(2) Tietz NW. Clinical Guide To Laboratory Tests. 3rd ed. Philadelphia,
    Pa: WB Saunders Co, 1995:366-367.

Methodology:

Electrochemiluminescence Immunoassay

Sample Processing:

Centrifuge at a speed and time necessary to get barrier separation of plasma/serum and cells within 1 hour of collection. Send specimen in original tube. Do Not transfer to another tube.
Each sample must be labeled with at least TWO full patient identifiers (First/Last Name & DOB are sufficient for non-UIHC affiliated clients) to avoid sample rejection/delays.

Sample Storage:

Refrigerate.
All sample storage requirements are intended for delivery to UIHC within 24 hours of collection for testing. If samples won't arrive in this time period, please call the UIHC Core Lab for alternative storage/shipping instructions (319-356-3527).

Transport Instructions:

Place labeled specimen into zip-lock type biohazard bag; seal bag.
Place completed requisition into outside pocket of bag.
Transport in cooler with refrigerated coolant packs.

See also:
Insulin, Random (Mailout), Serum or Plasma

See Additional Information:
Fasting Specimen Requirements
Biotin Interference with Immunoassays