Insulin, Free, Serum
NY State Approved Indicates the status of NY State approval and if the test is orderable for NY State clients.
Management of diabetes mellitus when the patient has known insulin autoantibodies
Automated Chemiluminescent Immunoenzymatic Assay System
Reporting Name A shorter/abbreviated version of the Published Name for a test; an abbreviated test name
Free Insulin, S
Free Insulin, Serum
Specimen Type Describes the specimen type needed for testing
Specimen Required Defines the optimal specimen. This field describes the type of specimen required to perform the test and the preferred volume to complete testing. The volume allows automated processing, fastest throughput and, when indicated, repeat or reflex testing.
Preferred: Red top
Acceptable: Serum gel
Submission Container/Tube: Plastic vial
Specimen Volume: 1 mL
1. Fasting. Non-fasting specimens are accepted for special studies.
2. Label specimens with corresponding draw time.
Additional Information: If multiple specimens are drawn, send separate order for each specimen.
Specimen Minimum Volume Defines the amount of specimen required to perform an assay once, including instrument and container dead space. Submitting the minimum specimen volume makes it impossible to repeat the test or perform confirmatory or perform reflex testing. In some situations, a minimum specimen volume may result in a QNS (quantity not sufficient) result, requiring a second specimen to be collected.
Mild reject; Gross reject
Mild OK; Gross OK
Mild OK; Gross OK
Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the laboratory. Alternate acceptable temperature(s) are also included.
|Serum||Frozen (preferred)||14 days|
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Insulin is a hormone produced by the beta cells of the pancreas.
Free insulin measurements should be comparable to routine insulin values in the absence of insulin antibodies.
Insulin autoantibodies may develop, however, in patients who have been injecting non human insulin for treatment of insulin-dependent diabetes. These antibodies will directly bind to insulin, making it unavailable for metabolic activity. The antibodies may also adversely affect the binding characteristics of insulin in immunoassays, making reliable quantitation difficult.
Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
1.4-14 micro IU/mL
During prolonged fasting, when the patient's glucose is reduced to <40.0 mg/dL, elevated insulin level plus elevated levels of proinsulin and C-peptide suggest insulinoma.
In patients with insulin-dependent diabetes mellitus, insulin levels generally decline.
In the early stage of noninsulin dependent diabetes mellitus (NIDDM), insulin levels are either normal or elevated.
In the late stage of NIDDM, insulin levels may also decline as levels of proinsulin decrease.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
No significant cautionary statements
Clinical Reference Provides recommendations for further in-depth reading of a clinical nature
1. Lassman-Vague V, Belicar P, Alessis C, et al: Insulin kinetics in type I diabetic patients treated by continuous intraperitoneal insulin infusion: influence of anti-insulin antibodies. Diabet Med 1996; 13(12):1051-1055
2. Hanning I, Home P, Alberti K: Measurement of free insulin concentrations: the influence of the timing of extraction of insulin antibodies. Diabetologia 1985;28(11):831-835
Method Description Describes how the test is performed and provides a method-specific reference
Specimen immunoglobulins are precipitated by adding an equal volume of 20% polyethylene glycol (PEG). The precipitate is removed by centrifugation and the supernatant analyzed using the Beckman ACCESS. The instrument is calibrated with standards which have also been subjected to the PEG treatment. The ACCESS insulin assay is a simultaneous "sandwich" assay which uses an anti-insulin mouse monoclonal antibody labeled with alkaline phosphatase and paramagnetic particles coated with a second mouse monoclonal anti-insulin antibody. A "sandwich" is formed by the 2 monoclonal antibodies binding to different antigenic sites on the insulin in the patient specimen. After separation in a magnetic field, all materials not bound to the solid phase are washed away. A chemiluminescent substrate is added to the reaction vessel and light genereated by the reaction is measured with a luminometer. The photon production is directly proportional to the concentration of insulin in the specimen and is determined by means of a stored, multi-point calibration curve. (Package insert: ACCESS Ultrasensitive Insulin 103765C. Beckman-Coulter Inc., Fullerton, CA)
Day(s) and Time(s) Test Performed Outlines the days and times the test is performed. This field reflects the day and time the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time required before the test is performed. Some tests are listed as continuously performed, which means assays are performed several times during the day.
Monday through Saturday; Continuously
Analytic Time Defines the amount of time it takes the laboratory to setup and perform the test. This is defined in number of days. The shortest interval of time expressed is "same day/1 day," which means the results may be available the same day that the sample is received in the testing laboratory. One day means results are available 1 day after the sample is received in the laboratory.
Maximum Laboratory Time Defines the maximum time from specimen receipt at Mayo Medical Laboratories until the release of the test result
Specimen Retention Time Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Performing Laboratory Location The location of the laboratory that performs the test
Test Classification Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer's instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR), Investigation Use Only (IUO) product, or a Research Use Only (RUO) product.
This test has been cleared or approved by the U.S. Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.
CPT Code Information Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Medical Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.
LOINC® Code Information Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the result codes returned for this test or profile.
|Result ID||Reporting Name||LOINC Code|
|FINS||Free Insulin, S||6901-3|