Dengue antigen test cassette (serum/plasma) is a lateral flow immunoassay for thequalitat-
-ive detection of dengue virus antigen in hum-an serum or plasma. It is intended to be used as a screening test and as an aid in the dia-
-gnosis of infection with dengue viruses. This test provides only a preliminary test result. Therefore more specific alternativediagnosis method must be used in order to obtain a confirmation of dengue infection.
Dengue antigen test cassette (serum/plasma) is designed to detect dengue virus antigen in human serum or plasma. The test cassette consists of:
A. a burgundy colored conjugate padcont-
-aining mouse anti-dengue NS1 antibody
conjugated with colloid gold (dengue antibody conjugates)
B. a nitrocellulose membrane strip containing a test line(T line) and a control line(C line). The T line is pre-coated with rabbit anti-dengue NS1 antibody, and the C line is pre-coated with goat anti-mouse IgG antibody. The antibodies to dengue antigen recognize the antigens from
all of the four serotypes of the dengue virus.
When an adequate volume of test specimen is dispensed into the sample well of the cassette, the specimen migrates
by capillary action across the test cassette. Dengue NS1 antigen if present in thespeci-
-men will bind to the dengue antibody conjugates. The immunocomplex is then captured on the membrane by the pre-coated rabbit anti-NS1 antibody, forming a burgundy colored T line, indicating a dengue antigen positive test result. Absence of the T line suggests a negative result. The test contains an internal control (C line) which should exhibit a burgundy colored line of the immuneocomplex of goat anti-mouse IgG/mouse IgG-gold conjugate regardless of the presence of colored T line. Otherwise, the test result is invalid and the specimen must be retested with another device.
REAGENTS AND MATERIALS PROVIDED
1. Each kit contains 40 test devices, each sealed in a foil pouch with three items inside:
a. One cassette device.
b. One pipette dropper.
c. One desiccant.
2. Sample buffer solution (1 bottle, 5ml)
3.One package insert (instruction for use).
For serum or plasma, collect blood into a container without anticoagulant. If the specimens are not immediately tested, they should be stored at 4-8°C for not more than 3 days. Specimens may be frozen at -20°C, but should not be repeatedly frozen and thawed.
Clotted specimens or specimens with microbial contamination must not be used.
Step 1: Bring the specimen and test components to room temperature if refrigerated or frozen. Mix the
specimen well prior to assay once thawed.
Step 2: When ready to test, open the pouch at the notch and remove device. Place the test device on a clean, flat surface.
Step 3: Be sure to label the device with specimen’s ID number.
Step 4: Fill the pipette with the specimen. Holding the dropper vertically (Reference as the below picture), dispense 1 drop (about 5 µL) of specimen into the sample well making sure that there are no air bubbles. Then add 1 drop (about 50µL) of Sample buffer solution immediately.
Step 5: Set up timer.
Step 6: Results can be read within 20 minutes. Positive results can be visible in as short as 1 minute. Don’t read result after 25 minutes. To avoid confusion, discard the test device after interpreting the result.
INTERPRETATION OF RESULTS
Negative:Only the control line is negative.
Positive: Both the control line and test line appear.
INVALID: Control line absent regardless of other lines indicates, test is invalid and must be repeated.
1. Must use fresh specimen and avoid repetitive freezing, the result will be invalid
2. Use it before expiry date.
3. The package of kit should not be opened until it reaches the room temperature if it taken out from the refrigerator. Use the test kit as soon as possible but within 1 hour after removal from pouch specially if the room temperature is more than 30°C and in high humidity environment.
4. Old Serum can not be used. If the serum is thick, it can be used only after being separated.
Limitations and Interferences
1. The test procedure, precautions and interpretation of results for the test must be strictly followed.
2. As with all diagnostic tests, the test result must be consistent with clinical findings.
3. Results are to be interpreted within the epidemiological, clinical and therapeutic context.
4. The use of icteric or lipemic samples should be avoided.
5. This test should not be used on specimens from immunosuppressed individuals.
6. Negative results must be confirmed at 20 minutes.
7. Results should not be read after 25 minutes.
STORAGE AND STABILITY
The test kit can be stored at room temperature (4 to 30°C) in the sealed pouch to the date of expiration. The kit has a shelf life of 24 months from the date of manufacture. The test kit should be kept away from direct sunlight, moisture and heat.