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Test ID: FRT3P    
T3 (Triiodothyronine), Free and Total, Serum

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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 total and free triiodothyronine (T3) assays are competitive-binding immunoenzymatic assays. For the total T3 assay, sample is added to a reaction vessel with a stripping agent to dissociate T3 from the binding proteins. T3 in the sample competes with the T3 analogue coupled to biotin for anti-T3 alkaline Phosphatase conjugate. Of the resulting antigen:antibody complexes, the T3 analogue:antibody complexes are bound to the streptavidin-coated solid phase. Separation in a magnetic field and washing removes the sample T3: antibody complexes and other materials not bound to the solid phase.

 

For the Free T3 (FT3) assay, sample is added to a reaction vessel with mouse monoclonal antitriiodothyronine (anti-T3) and paramagnetic particles coated with goat antimouse capture antibody. During the first incubation, free T3 in the sample reacts with the anti-T3 antibody and is subsequently bound to the capture antibody. After incubation in a reaction vessel, materials bound to the solid phase are held in a magnetic field, while unbound materials are washed away. Next, T3-alkalinephosphatase conjugate and buffer are added to the reaction vessel to react with the remaining anti-T3 antibody binding sites. After incubation in a reaction vessel, materials bound to the solid phase are held in a magnetic field, while unbound materials are washed away. For both the total T3 and the FT3 assays, the chemiluminescent substrate Lumi-Phos* 530 is added to the vessel and light generated by the reaction is measured with a luminometer. The light production is inversely proportional to the concentration of total and FT3 in the sample. The amount of analyte in the sample is determined from a stored, multipoint calibration curve.(Package Insert: Beckman Coulter Ireland Inc. Ireland, 2005)

PDF Report Indicates whether the report includes an additional document with charts, images or other enriched information

No

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; 3rd shift

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.

1 day

Maximum Laboratory Time Defines the maximum time from specimen receipt at Mayo Medical Laboratories until the release of the test result

3 days

Specimen Retention Time Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded

1 month

Performing Laboratory Location The location of the laboratory that performs the test

New England