Free T3 in Human Serum with Roche e801

Detection of Calcium in Human Serum with Roche c502

Test Name: Detection of Free T3 in Human Serum with Roche e801

Test Name: This immunoassay is for the in vitro quantitative determination of free T3 (free triiodothyronine) in human serum and plasma.
Method Name: In the Elecsys FT3 III assay a specific anti-T3 antibody labeled with a ruthenium complex is used to determine the free triiodothyronine concentration.
Results: Technical Range: 0.39-32.6 pg/mL Reportable Range: 1.42-15.2 pg/mL
Reference Ranges: Age Value
1 day – 23 months 3.3 – 5.2 pg/mL
2 yrs – 12 yrs 3.3 – 4.9 pg/mL
13 yrs – 20 yrs 2.9 – 4.5 pg/mL
21 yrs – 999 yrs 2.2 – 4.0 pg/mL
Clinical Significance: The thyroid hormones triiodothyronine (T3) and thyroxine (T4) are secreted into the bloodstream by the thyroid gland and play a vital role in regulating the body’s metabolic rate, influencing the cardiovascular system, growth, and bone metabolism, and are important for normal development of gonadal functions and nervous system.

T3 circulates in the bloodstream as an equilibrium mixture of free and serum bound hormone. Free T3 (fT3) is the unbound and biologically active form, which represents only 0.2-0.4 % of the total T3. The remaining T3 is inactive and bound to serum proteins, while the distribution of T3 between these binding proteins (thyroxine binding globulin, pre-albumin, albumin) is controversially discussed.

The determination of free T3 has the advantage of being independent of changes in the concentrations and binding properties of the binding proteins; additional determination of a binding parameter (T uptake, TBG) is therefore unnecessary. Therefore, free T3 is a useful tool in clinical routine diagnostics for the assessment of the thyroid status. Free T3 measurements support the differential diagnosis of thyroid disorders, are needed to distinguish different forms of hyperthyroidism, and to identify patients with T3 thyrotoxicosis.

A variety of methods are available for estimating the free thyroid hormone levels. The direct measurement of fT4 and fT3 via equilibrium dialysis or ultrafiltration is mainly used as a reference method for standardizing the immunological procedures generally used for routine diagnostic purposes.

Submission Criteria: For specimen collection and preparation, only use suitable tubes or collection containers.
Only the specimens listed below were tested and found acceptable.
Serum
Plasma: Li-heparin and K2-EDTA plasma
Do not use fluoride plasma

The sample types listed were tested with a selection of sample collection tubes that were commercially available at the time of testing, therefore not all available tubes of all manufacturers were tested. Sample collection systems from various manufacturers may contain differing materials which could affect the test results in some cases.  When processing samples in primary tubes (sample collection systems), follow the instructions of the tube manufacturer.
Storage and Stability:    30 days at -20°C
7 days at 2-8°C
5 days at 20-25°C

Rejection Criteria: Rejection criteria include but are not limited to:
1. Specimens containing fibrin or clots.
2. Excessive platelet clumping
3. Leaking specimens
4. Substandard mixing or collection
5. Expired or improperly stored collection tubes.
6. Improperly filled tubes based on collection tube manufacturer’s guidelines.
7. Contaminated specimens (IV fluid, foreign particles, etc.)
8. Specimens not analyzed within the appropriate time frame.
9. Samples not shipped at appropriate temperature.
10. Samples without 2 proper identifiers or samples having identifiers that do not match the electronic or paper lab requisition.
Authorization: Diagnostic testing can only be performed with approval from an authorized provider/agency.
Turn Around Time: 1 day.
Method Name: Photometrical measurement of the complex formed when calcium ions react with 5-nitro-BAPTA (NM-BAPTA) and EDTA. The change in absorbance is directly proportional to the calcium concentration.
Results: Technical Range: 0.8-20.1 mg/dL
Reportable Range: 1.2-17.88 mg/dL
Reference Ranges: <1 year: 8.7-11.0 mg/dL 1-17 years: 9.3-10.6 mg/dL 18-59 years: 8.6-10.0 mg/dL ≥60 years: 8.8-10.2 mg/dL
Clinical Significance: Calcium is the most abundant mineral element in the body with about 99% in the bones primarily as hydroxyapatite. The remaining calcium is distributed between the various tissues and the extracellular fluids where it performs a vital role for many life-sustaining processes. Among the extra skeletal functions of calcium are involvement in blood coagulation, neuromuscular conduction, excitability of skeletal and cardiac muscle, enzyme activation, and the preservation of cell membrane integrity and permeability.

Serum calcium levels and hence the body content are controlled by parathyroid hormone (PTH), calcitonin, and vitamin D. An imbalance in any of these modulators leads to alterations of the body and serum calcium levels. Increases in serum PTH or vitamin D are usually associated with hypercalcemia. Increased serum calcium levels may also be observed in multiple myeloma and other neoplastic diseases. Hypocalcemia may be observed e.g., in hypoparathyroidism, nephrosis, and pancreatitis.

Submission Criteria: For specimen collection and preparation, only use suitable tubes or collection containers.
Only the specimens listed below were tested and found acceptable.
Serum
Plasma: Li-heparin and K2-EDTA plasma
Do not use ammonium heparin

The sample types listed were tested with a selection of sample collection tubes that were commercially available at the time of testing, therefore not all available tubes of all manufacturers were tested. Sample collection systems from various manufacturers may contain differing materials which could affect the test results in some cases.  When processing samples in primary tubes (sample collection systems), follow the instructions of the tube manufacturer.
Storage and Stability:    240 days at (-15°C) – (-25°C)
21 days at 2-8°C
7 days at 20-25 °C

Rejection Criteria: Rejection criteria include but are not limited to:
1. Specimens containing fibrin or clots.
2. Excessive platelet clumping
3. Leaking specimens
4. Substandard mixing or collection
5. Expired or improperly stored collection tubes.
6. Improperly filled tubes based on collection tube manufacturer’s guidelines.
7. Contaminated specimens (IV fluid, foreign particles, etc.)
8. Specimens not analyzed within the appropriate time frame.
9. Samples not shipped at appropriate temperature.
10. Samples without 2 proper identifiers or samples having identifiers that do not match the electronic or paper lab requisition.
Authorization: Diagnostic testing can only be performed with approval from an authorized provider/agency.
Turn Around Time: 1 day.