Specimen:

Plasma

Collection Medium:

Alternate
Collection Media:

Call laboratory for additional acceptable specimen collection 
containers.

Minimum:

5 mls whole blood from light green top tubes or three 0.6 microtubes 
from a fasting patient.

Delivery Instructions:

Deliver to laboratory immediately after collection.

Testing Schedule:

Batch analysis performed on Tuesdays and Fridays.  Sample must 
be received by 0800 for same day service.  For additional services, 
contact Clinical Pathology Resident on-call at pager #3404.

Reference Range:

2.6 -  24.9 micro U/mL (fasting)

Comments:

This insulin assay does NOT measure the insulin analogs lispro 
(Humalog), aspart (NovoLog), and glargine (Lantus). Please contact the 
laboratory if an assay with crossreactivity to  these  insulin analogs 
is required.

This assay will allow measurement of free insulin by removal of
anti-insulin antibodies with PEG.  The laboratory will report results
both with PEG precipitation (free insulin) and without PEG
precipitation (total insulin).

A glucose will be automatically done on each specimen at no
additional charge.

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 interferes.

In patients receiving therapy with high biotin doses (i.e. is greater 
than 5 mg/day) no sample should be taken until at least 8 hours after 
the last biotin administration.

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

CPT Code:

83525

See Additional Information:
Fasting Specimen Requirements
Specimens Requiring Immediate Delivery