FT4 Test Cassette is intended for in vitro quantitative determination of
free Thyroxine (FT4) in human whole blood, serum or plasma. Measurement of FT4 is used as an aid
to assessment of thyroid function.
【SUMMARY】
Thyroid hormones are two hormones produced and released by the thyroid gland,
namely triiodothyronine (T3) and thyroxine (T4). They are tyrosine-based hormones
that are primarily responsible for regulation of metabolism. The major form of thyroid
hormone in the blood is thyroxine (T4), which has a longer half-life than T3.1 In humans,
the ratio of T4 to T3 released into the blood is approximately 14:1.2So the thyroxine(T4)
is a primary diagnostic marker for thyroid function.
The thyroid hormones act on nearly every cell in the body. They act to increase
the basal metabolic rate, affect protein synthesis, help regulate long bone growth
(synergy with growth hormone) and neural maturation, and increase the body's
sensitivity to catecholamines (such as adrenaline) by permissiveness. The thyroid
hormones are essential to proper development and differentiation of all cells of the
human body. These hormones also regulate protein, fat, and carbohydrate metabolism,
affecting how human cells use energetic compounds. They also stimulate vitamin
metabolism. Numerous physiological and pathological stimuli influence thyroid
hormone synthesis.
Most of the thyroid hormone circulating in the blood is bound to transport proteins, and
only a very small fraction is unbound and biologically active. Therefore, triiodothyronine
(T3) and thyroxine (T4) measured as free T3 and free T4 can more accurately reflect
the functional status of the thyroid.
【PRINCIPLE】
The FT4 Test Cassette detects FT4 based on Fluorescence
Immunoassay. The sample moves through the strip from sample pad to absorbent pad.
FT4 in the sample will compete with the T4 antigen coated on the membrane. The less
FT4 in the sample, the more fluorescent microspheres conjugated with anti-T4
antibodies can be captured by the T4 antigen coated on the membrane (Test line). The
concentration of FT4 in the sample is inversely related to the intensity of the fluorescent
signal captured on the T line. According to the fluorescence intensity of the test and the
standard curve, the concentration of FT4 in the sample can be calculated by the
【REAGENTS】
The test include T4 antibody coated particles and T4-BSA antigen coated on the
membrane.
【PRECAUTIONS】
1. For professional in vitro diagnostic use only.
2. Do not use after the expiration date indicated on the package. Do not use the test if
the foil pouch is damaged. Do not reuse.
3. This test contains products of animal origin. Certified knowledge of the origin and/or
sanitary state of the animals does not completely guarantee the absence of
transmissible pathogenic agents. It is therefore recommended that these products
be treated as potentially infectious, and handled observing usual safety precautions
(e.g., do not ingest or inhale).
4. Avoid cross-contamination of specimens by using a new specimen collection
container for each specimen obtained.
5. Do not eat, drink or smoke in the area where the specimens and tests are handled.
Handle all specimens as if they contain infectious agents. Observe established
precautions against microbiological hazards throughout the procedure and follow
standard procedures for proper disposal of specimens. Wear protective clothing
such as laboratory coats, disposable gloves and eye protection when specimens
are assayed.
6. Do not interchange or mix reagents from different lots.
7. Humidity and temperature can adversely affect results.
8. Used testing materials should be discarded in accordance with local regulations.
9. Read the entire procedure carefully prior to any testing.
10. The FT4 Test Cassette is only operational in the FIA Analyzer. And tests should be
applied by professionally trained staff working in certified laboratories at some
remove from the patient and clinic at which the sample(s) is taken by qualified
medical personnel.
【STORAGE AND STABILITY】
1. The test should be stored at 4-30 °C until the expiry date printed on the sealed
pouch.
2. The test must remain in the sealed pouch until use.
3. Do not freeze.
4. Care should be taken to protect the components of the test from contamination.
5. Do not use if there is evidence of microbial contamination or precipitation. Biological
contamination of dispensing equipment, containers or reagents can lead to false
results.
【SPECIMEN COLLECTION AND PREPARATION】
• Specimen Collection
Collect the specimens according to standard procedures.
EDTA K2, Citrate sodium and Potassium Oxalate can be used as the anticoagulant for
collecting the plasma specimens.
A clean tube without anticoagulants can be used to collect serum specimens.
• Specimen Storage and Shipping
Serum and plasma specimens may be stored at 2-8 °C for up to 7 days, and -20 °C for
long term. Frozen specimens should be thawed and mixed before testing. Specimens
should not be frozen and thawed repeatedly.
If specimens are to be shipped, these should be packed in compliance with local
regulations covering the transportation of etiological agents.
• Preparation
Before performing the test, please balance the sample to room temperature (15-30 °C).
Frozen specimens must be completely thawed and mixed well prior to testing.
【MATERIALS】
Materials Provided
• Test Cassettes
• Specimen Collection Tubes With Buffer
• ID Card
• Package Insert
Materials Required But Not Provided
• Timer
• Centrifuge
• Fluorescence Immunoassay Analyzer
• Pipettes
• Specimen Collection Containers
【DIRECTIONS FOR USE】
Refer to FIATEST GO Fluorescence Immunoassay Analyzer User Operation Manual
for the complete instructions for the use of analyzer. The test should be conducted at
room temperature.
Allow the test, specimen, buffer and/or controls to reach room temperature
(15-30 °C) prior to testing.
1. Turn on the Analyzer power.
2. Take out the ID card and insert it into the Analyzer ID Card Slot. Choose test mode
and/or sample type according to needs.
3. Remove the test cassette from the sealed foil pouch and use it within 1 hour. Best
results will be obtained if the assay is performed immediately after opening the foil
pouch.
4. Place the test on a flat and clean surface.
Serum or plasma: Pipette 75 μL of serum or plasma into the buffer tube; mix the
specimen and the buffer well.
5. Add diluted specimen with a Pipette: Pipette 75 μL of diluted specimen into the
sample well. Start the timer at the same time.
6. Test results should be interpreted at 15 minutes with the use of Fluorescence
Immunoassay Analyzer.
Caution: There are different test modes of the Fluorescence Immunoassay
Analyzer. The difference between them is incubation of the test cassette is outside
or inside the analyzer. Choose test mode accordingly and confirm sample type.
Consult the user manual of the analyzer for detailed operation information.
Operator must consult the Fluorescence Immunoassay Analyzer User Manual prior
to use and become familiar with the processes and quality control procedures.
