Insulin, Free, Serum
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