*All pictures shown are for illustration purpose only.
EWB COVID-19 Rapid Antigen Test Kit (Saliva) is a colloidal gold-based lateral flow immunoassay intended for the qualitative detection of SARS-CoV-2 nucleocapsid antigen in saliva specimens from individuals who are suspected of COVID-19. The COVID-19 viral antigen is detectable in saliva samples during the acute phase of infection.
The results are for the identification of SARS-CoV-2 antigen. Positive results indicate the presence of viral antigens, but correlation with patient history and other diagnostic information is necessary to determine the infection status. Positive results do not rule out bacterial infection or co-infection with other viruses.
Negative results do not rule out SARS-CoV-2 infection and should not be used as the sole basis for treatment or patient management decisions, including infection control decisions. Negative results should be considered in the context of patient’s recent exposures, history and the presence of clinical signs and symptoms consistent with COVID-19, and confirmed with a molecular assay, if necessary, for patient management.
EWB COVID-19 Rapid Antigen Test Kit (Saliva) is for in vitro diagnostic use only.
lmmunochromatography is applied as the test principle. In general, the SARS -CoV-2 antigen in the saliva sample binds with the colloidal gold labelled anti-SARS-CoV-2 nucleocapsid antibodies in the cartridge to form the immunocomplexes. When the complexes migrate to the test ‘T’ line (coated with anti-SARS-CoV-2 nucleocapsid antibodies), the complexes that contain the SARS-CoV-2 antigen will be captured and form a colored line in the T line region, which indicates the sample is positive for SARS -CoV-2 antigen. Similarly, the colloidal gold labelled chicken lgY antibody will be captured in the control ‘C’ line (coated with goat anti-chicken lgY). A colored line will also appear in the control line region which indicates the correct operation procedure has been taken and the assay is providing reliable results. A single line at the control line region indicating negative result where there is no detection of SARS-CoV -2 antigen.
EWB COVID-19 Rapid Antigen Test Kit (Saliva) employed an innovative detection method that uses Colloidal Gold as a conjugate to detect SARS-CoV-2 viral nucleoprotein antigens from saliva samples.
Viral antigen detection has been used as a candidate strategy for the early diagnosis of COVID-19 infection. Since nucleocapsid protein is known as one of the main expressed structural proteins, it has been confirmed as an ideal target for viral antigen-based detection. Therefore, nucleoprotein antigen detection method is one of the most powerful methods that is widely used in clinical testing today.
- The reagent cartridge is packaged separately with a bag of desiccant.
- Each cartridge is for a single test and consists of the nitrocellulose membrane, sample pad, conjugate pad, absorbent paper, and PVC board .
- The nitrocellulose membrane is coated with anti-SARS-CoV-2 antibody and goat anti-chicken lgY. The conjugate pad contains colloidal gold labelled anti-SARS-CoV-2 antibody and chicken lgY.
- The extraction tube consists of 500ul of extraction buffer and has a purple dropper lid.
MATERIALS REQUIRED BUT NOT PROVIDED
- Any necessary personal protective equipment
STORAGE AND STABILITY
Store the kits at 2°C to 30°C in a dry place and avoid direct sunlight. The unopened cartridges are stable until the expiry date printed on the package labels. Once opened, they should be used immediately.
- Clean the mouth 30 minutes before collecting a saliva sample. Do not eat, drink, smoke or chew gum within 30 minutes before giving your sample. Place the tip of the tongue against the root of the upper or lower jaw to enrich the saliva.
- Gently spit into the paper.
- Remove the cartridge from the package and place it on a clean, flat and dry surface. Label the cartridge with patient’s name.
- Remove the dropper lid from the extraction tube containing extraction buffer.
- Use a disposable pipette to transfer the saliva (filled to the bottom of the suction head) into the extraction tube.
- Tighten the dropper lid and mix the contents gently by inverting the tube several times.
- Leave the mixture in the extraction tube to stand for 1 minute.
- Remove the white cap on the top of the dropper lid and add two drops (around 7uL) of the well-mixed sample into the sample well of the cartridge.
- Leave the sample-loaded cartridge at room temperature for 12 minutes.
- Read the results after 12 minutes of incubation. Do not interpret results after 15minutes (from addition of the sample).
INTERPRETATION OF RESULTS
- The Control (C) line must appear for the test to be valid regardless of the appearance of the T line.
- Failure to observe the control line indicate unreliable result. When this happens, please check the operating procedures carefully and test again with a new cartridge
- The EWB COVID-19 Rapid Antigen Test Kit (Saliva) is only for qualitative detection of the SARS-CoV-2 antigen.
- Results obtained with this kit should not be used as the sole criteria for diagnosis and treatment of SARS-CoV-2 infection. The clinical symptoms, medical history, epidemiological information and other laboratory findings of patients should always be taken into consideration.
The clinical performance of EWB COVID-19 Rapid Antigen Test Kit (Saliva) was determined by testing paired nasopharyngeal (NP) swab and saliva samples from 357 persons suspected of COVID-19 infection. The samples were collected within 5 days post onset of symptoms or suspected exposure. The NP samples were shipped to laboratory and determined to be positive or negative using RT-PCR method. The saliva samples were tested directly at the collection site with the EWB COVID-19 Rapid Antigen Test Kit (Saliva).
WARNING AND PRECAUTIONS
- Do not use if the test kit is damage or beyond expiration date.
- Do not use perforated paper pouch.
- Extraction Buffer of different lots are not interchangeable. The results may not be reliable if reagents from different lots are mixed or used together.
- The reagent cartridge is for single test and cannot be reused.
- Do not eat the desiccant.
- Treat all specimens as potentially infectious. Be cautious and follow universal precautions in sample collection and handling.
- The samples, used reagents and consumables are medical waste which are potentially hazardous and should be disposed of in accordance with national and local regulations.