Span Biotech Ltd.

 Intended Use

The Dengue NS1 Ag-IgG/IgM Combo Test is a rapid chromatographic immunoassay for the qualitative detection of antibodies (IgG and IgM) and dengue virus NS1 antigen to dengue virus in Whole Blood /Serum / Plasma to aid in the diagnosis of Dengue viral infection.

Summary

Dengue is transmitted by the bite of an Aedes mosquito infected with any one of the four dengue viruses. It occurs in tropical and sub-tropical areas of the world. Symptoms appear 3—14 days after the infective bite. Dengue fever is a febrile illness that affects infants, young children and adults. Dengue haemorrhagic fever (fever, abdominal pain, vomiting, bleeding) is a potentially lethal complication, affecting mainly children. Early clinical diagnosis and careful clinical management by experienced physicians and nurses increase survival of patients. Dengue NS1 Ag-IgG/IgM Combo Test is a simple, visual qualitative test that detects dengue virus antibodies and dengue virus NS1 antigen in human Whole Blood/serum/plasma. The test is based on immunochromatography and can give a result within 15 minutes. 

Principle

The Dengue NS1 Ag-IgG/IgM Combo Test is a qualitative membrane strip based immunoassay for the detection of dengue virus antibodies (IgG and IgM) and dengue virus NS1 antigen in Whole Blood /Serum / Plasma.

For IgG/IgM Test :The test device consists of: 1) a burgundy colored conjugate pad containing dengue recombinant envelope antigens conjugated with Colloid gold (dengue conjugates), 2) a nitrocellulose membrane strip containing two test lines (T1 and T2 lines) and a control line (C line). The T1 line is pre-coated with the antibody for the detection of IgM anti-dengue, T2 line is coated with antibody for the detection of IgG anti-dengue. When an adequate volume of test specimen is dispensed into the sample well of the test cassette, the specimen migrates by capillary action across the cassette. IgG anti-dengue, if present in the specimen, will bind to the dengue conjugates. The immunocomplex is then captured by the reagent pre-coated on the T2 band, forming a burgundy colored T2 line, indicating a dengue IgG positive test result and suggesting a recent or repeat infection. IgM anti-dengue if present in the specimen will bind to the dengue conjugates. The immunocomplex is then captured by the reagent coated on the T1 line, forming a burgundy colored T1 line, indicating a dengue IgM positive test result and suggesting a fresh infection. Absence of any T lines (T1 and T2) suggests a negative result.

For NS1 Test: In this test procedure, anti-Dengue NS1 antibody is immobilized in the test line region of the cassette. After a Whole Blood /Serum / Plasma specimen is placed in the specimen well, it reacts with anti-Dengue NS1 antibody coated particles that have been applied to the specimen pad. This mixture migrates chromatographically along the length of the test strip and interacts with the immobilized anti-Dengue NS1 antibody. If the specimen contains dengue virus NS1 antigen, a colored line will appear in the test line region indicating a positive result. If the specimen does not contain dengue virus NS1 antigen, a colored line will not appear in this region indicating a negative result.

To serve as a procedural control, a colored line will always appear at the control line region indicating that proper volume of specimen has been added and membrane wicking has occurred.

Storage and Stability

Store as packaged in the sealed pouch at room temperature or refrigerated (4-30℃ or 40-86℉). The test device is stable through the expiration date printed on the sealed pouch.

The test must remain in the sealed pouch until use.

Additional Special Equipment

Materials Provided

Ÿ    Test devices                         Ÿ    Disposable specimen droppers   

Ÿ    Buffer                                   Ÿ    Package insert

Materials Required But Not Provided

Ÿ    Timer                                Ÿ    Centrifuge

Ÿ    Specimen collection containers        

 Precautions

1.For professional in vitro diagnostic use only. Do not use after expiration date.

2.Do not eat, drink or smoke in the area where the specimens and kits are handled.

3.Handle all specimens as if they contain infectious agents.

4.Observe established precautions against microbiological hazards throughout all procedures and follow the standard procedures for proper disposal of specimens.

1.Wear protective clothing such as laboratory coats, disposable gloves and eye protection when specimens are assayed.

2.Follow standard biosafety guidelines for handling and disposal of potential infective material.

3.Humidity and temperature can adversely affect results.

Specimen Collection and Preparation

1.The Dengue NS1 Ag-IgG/IgM Combo Test can be performed used on Whole Blood /Serum / Plasma.

2.To collect whole blood, serum or plasma specimens following regular clinical laboratory procedures.

3.Testing should be performed immediately after specimen collection. Do not leave the specimens at room temperature for prolonged periods. For long term storage, specimens should be kept below -20℃. Whole blood should be stored at 2-8℃ if the test is to be run within 2 days of collection. Do not freeze whole blood specimens.

4.Bring specimens to room temperature prior to testing. Frozen specimens must be completely thawed and mixed well prior to testing. Specimens should not be frozen and thawed repeatedly.

Test Procedureure

Allow the test, specimen, buffer and/or controls to reach room temperature 15-30℃ (59-86℉) prior to testing.

1.Bring the pouch to room temperature before opening it. Remove the test device from the sealed pouch and use it as soon as possible.Place the test device on a clean and level surface.

2.For IgG/IgM Test :Hold the dropper vertically and transfer 1 drop of specimen (approximately 10μl) to the specimen well(S) of the test device, then add 2 drops of buffer (approximately 70μl) and start the timer. See illustration below.

3.For NS1Test:

· For serum or plasma specimen: Hold the dropper vertically and transfer 8~10 drops of serum or plasma (approximately 100μl) to the specimen well(S) of the test device, then start the timer. See illustration below.

· For whole blood specimens: Hold the dropper vertically and transfer 3 drops of whole blood(approximately 35μl) to the specimen well(S) of the test device, then add 2 drops of buffer (approximately 70μl) and start the timer. See illustration below.

4.Wait for the colored line(s) to appear. Read results at 15 minutes. Do not interpret the result after 20 minutes.

Notes:

Applying sufficient amount of specimen is essential for a valid test result. If migration (the wetting of membrane) is not observed in the test window after one minute, add one more drop of buffer or specimen to the specimen well. 

Interpretation of Results

Positive:

For IgG/IgM Test: Control line and at least one test line appear on the membrane. The appearance of T2 test line indicates the presence of dengue specific IgG antibodies. The appearance of T1 test line indicates the presence of dengue specific IgM antibodies. And if both T1 and T2 line appear, it indicates that the presence of both dengue specific IgG and IgM antibodies. The lower the antibody concentration is, the weaker the result line is.

For NS1 Test: Two lines appear. One line should always appear in the control line region(C), and another one apparent colored line should appear in the test line region.

Negative: One colored line appears in the control region(C).No apparent colored line appear in the test line region.

Invalid: Control line fails to appear. Insufficient specimen volume or incorrect procedural techniques are the most likely reasons for control line failure. Review the procedure and repeat the test with a new test device. If the problem persists, discontinue using the test kit immediately and contact your local distributor.

Limitations

1.The Dengue NS1 Ag-IgG/IgM Combo Test is for in vitro diagnostic use only. The test should be used for the detection of dengue antibodies and dengue virus NS1 antigen in Whole Blood /Serum / Plasma specimens only.

2.As with all diagnostic tests, all results must be interpreted together with other clinical information available to the physician.

3.If the test result is negative and clinical symptoms persist, additional testing using other clinical methods is recommended. A negative result does not at any time preclude the possibility of Dengue viral infection.