Test ID: FRT3
T3 (Triiodothyronine), Free, Serum
Method Description
Describes how the test is performed and provides a method-specific reference
The instrument used is a Beckman Coulter DxI 800. The Access Free triiodothyronine (T3) assay is a competitive-binding immunoenzymatic assay. A sample is added to a reaction vessel with an anti-T3 monoclonal antibody conjugated to alkaline phosphatase. During the incubation, free T3 in the sample reacts with the anti-T3 antibody. Particles coated with streptavidin and biotinylated T3 analog are then added to the mixture. Unoccupied binding sites on the anti-T3 antibody are bridged to the particle through the T3 analog. After incubation in a reaction vessel, materials bound to the solid phase are held in a magnetic field, while unbound materials are washed away. Chemiluminescent substrate Lumi-Phos 530 is added to the vessel and the light generated by the reaction is measured with a luminometer. The light production is inversely proportional to the concentration of free T3 in the sample. The amount of analyte in the sample is determined from a stored, multipoint calibration curve. (Beckman Coulter Assay Manual 2007)
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 Friday; 5 a.m.-12 a.m.
Saturday; 6 a.m.-6 p.m.


