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Test ID: HCASC    
Hemochromatosis Cascade

Method Description Describes how the test is performed and provides a method-specific reference

Iron is liberated from transferrin under acidic conditions. Ascorbate reduces the released Fe(3+) ions to Fe(2+) ions, which react with FerroZine to form a colored complex which is measured photometrically at 570 nm. The color intensity is directly proportional to the concentration of iron present.(Package insert: Roche Fe reagend, Roche Diagnostics, Indianapolis, IN, 2010)

 

Anti-transferrin antibodies react with the antigen in the sample to form an antigen/antibody complex. Following agglutination, this is measured turbidimetrically. Addition of polyethylene glycol (PEG) allows the reaction to progress rapidly to the end point and increases sensitivity.(Package insert: Roche TRSF2 reagent. Indianapolis, IN, 2005). The total iron binding capacity (TIBC) is dependent on transferrin concentration and can be calculated. The percent saturation is calculated using the iron and total iron-binding capacity concentrations by the following equation: % saturation = iron/TIBC x 100.

 

The ferritin assay is a 2-site immunoenzymatic ("sandwich") assay. A sample is added to a reaction vessel with goat anti-ferritin-alkaline phosphatase conjugate, and paramagnetic particles coated with goat anti-mouse: mouse anti-ferritin complexes. Serum or plasma (heparin) ferritin binds to the immobilized monoclonal anti-ferritin on the solid phase, while the goat anti-ferritin enzyme conjugate reacts with different antigenic sites on the ferritin molecules. After incubation in a reaction vessel, materials bound to the solid phase are held in a magnetic field while unbound materials are washed away. Then, 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 directly proportional to the concentration of ferritin in the sample. The amount of analyte in the sample is determined from a stored, multipoint calibration curve. The instrument used is a Beckman Coulter Unicel DXI 800.(Package Insert: Beckman Coulter Ireland Inc, Ireland, 2003)

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 Sunday; 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.

Same day/1 day

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

1 day

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

7 days

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

Rochester