LFIA SARS-CoV-2 Antigen Test Kit Instruction Manual
- June 5, 2024
- LFIA
Table of Contents
LFIA SARS-CoV-2 Antigen Test Kit
Product Name
Intended Use
SARS-CoV-2 antigen Test Kit (LFIA) is a kind of Colloidal gold immunochromatographic technology reagent. It is intended to qualitatively detect the SARS-CoV-2 virus in people having symptoms within 7 days. It is intended to be used by a health professional or a laboratory professional. It uses human anterior nasal secretion, nasopharyngeal secretion, or throat secretion for testing. It is an aid for diagnosis, and results should not be used as the sole basis to diagnose or exclude SARS-CoV-2 infection.
Test Principle
Medics SARS-CoV-2 antigen Test Kit (LFIA) detects the SARS-CoV-2 nucleocapsid antigens with colloidal gold immunochromatography using a double-antibody sandwich assay. The test cassette contains (1) colloidal gold-labeled anti- SARS-CoV-2 Nucleocapsid Protein antibody, (2) one detection T line, and one quality control Cline xed on a nitrocellulose membrane. T line is xed with another anti-SARS-CoV-2 Nucleocapsid Protein antibody for detecting SARS- CoV-2. The quality control antibody is xed on the Cline. When the appropriate amount of test sample treated with lysis butter is added to the sample well of the test cassette, the sample will move forward along the test strip via capillary action. If the sample contains SARS-CoV-2 nucleocapsid antigens and the concentration is higher than the limit of detection, the antigens will bind to the colloidal gold-labeled anti-SARS-CoV-2 Nucleocapsid Protein antibody. The immune complex will be captured by another anti-SARS-CoV-2 Nucleocapsid Protein antibody immobilized on the membrane, forming a red T line and indicating a positive result for SARS-CoV-2. If the sample contains no SARS-CoV-2 nucleocapsid antigens or the concentration is lower than the limit of detection, a negative result is displayed. Additionally, the test cassette also contains a quality control Cline. Regardless of what nucleocapsid antigens are present, the Cline should appear to indicate that the sample has been transported properly through the membrane. If the Cline does not appear, it indicates that the test result is invalid and the sample is required to retest.
Mutation Virus Detection Compatibility Tips
SARS-CoV-2 antigen Test Kit(LFIA) detects Nucleocapsid protein, NOT spike protein of SARS-CoV-2.The mutations of SARS-CoV-2 variants B.1.1.7/B.1.351/B.1.1.28(P.1 /B.1.617.1/B.1.617.2/B.1.526/B.1.427/B.1.429 have to be confirmed. All of those variants of Nucleocapsid proteins can be effectively detected by the SARS-CoV-2 antigen Test Kit(LFIA)
Test Kit Contents
- Type I test kit contains test cassettes, sterile swabs, sampling tubes, a vial containing lysis buffer, droppers and instructions for use.
- Type II test kit contains test cassettes, sterile swabs, sampling tubes containing individual lysis buffer, droppers and instructions for use.
- Type Ill test kit contains test cassettes, sterile swabs, sampling tubes, buffer capsules containing individual lysis buffer, droppers and instructions for use.
- Test cassette contains test strip, cassette, and desiccant. The test strip contains colloidal gold-labeled anti-SARS-CoV-2 Nucleocapsid Protein antibody, nitrocellulose membrane (C line fixed with goat-anti-mouse lgG polyclonal antibody, and T line fixed with another anti-SARS-CoV-2 Nucleocapsid Protein antibody).
Warnings and Precautions
- This test kit is used for in vitro diagnosis only.
- This test kit should be used by qualified personnel with professional experience or proper training.
- This test kit should be used within 1 hour after opening the package, and samples from transport media will reduce sensitivity. The test cassette should not be used if being wet or polluted.
- Proper protection should be taken during testing to avoid splashing when adding sample.
- Dispose of all used or damaged test cassettes, sampling tubes, droppers, swabs, or other kit components as biohazardous materials.
- Negative results do not rule out SARS-CoV-2 infection, particularly in those who have been in contact with the virus.
- For the detection of SARS-CoV-2 and unexpected variants (mutant strains),the changes of epitopes caused by mutation sites of Nucleocapsid Protein may reduce the analytical sensitivity of the reagent and lead to false negative results.
Storage Instructions
The test kit should be stored away from direct sunlight at 2℃ to 30℃ with a shelf-life of 24 months. Do not freeze.
Sample Requirements
One test cassette can only be used to test one sample type. Sample types
include nasopharyngeal secretion, throat secretion and nasal secretion.
- Anterior Nasal Sampling： Insert the swab into a nostril (2.5 cm). Be sure to collect any nasal drainage that may be present. Carefully rotate the swab in a circular path against the inside of the nostril at least 5 times. Using the same swab repeat the procedure in the other nostril.
- Nasopharyngeal secretion collection: Take out a swab from the pouch. Insert the swab into one of the patient’s nostrils until it reaches the posterior nasopharynx where there is the most secretion, gently rotate and rub the swab over the surface of the posterior nasopharynx for several times before taking it out.
- Throat secretion collection: Insert the whole swab completely into the throat from the mouth, centering on the throat wall and the reddened area of the palate tonsil, wipe both sides of the pharyngeal tonsil and posterior pharyngeal wall with moderate force. Try to avoid the tongue before taking it out.
The sample should be treated with lysis buffer provided in this kit as soon as possible after collection. If the sample cannot be processed immediately, it should be stored immediately in a dry, sterilized and strictly sealed plastic tube. It can be stored at 2℃-8℃ for 8 hours. Could be stored at -70℃ for 3 months.
Test Procedure
Do not open the pouch until ready to use. Prep necessary materials: Timer |
Tube rack for sampling tubes and specimens | Any necessary personal protective
equipment. (Disposable working cap、Double chemical impermeable
gloves、Isolation gowns 、Helmet with breathing apparatus、A pair of
goggles、Rubber bottom shoes 、Waterproof protective foot covers) Test
procedures: Open the aluminum foil pouch, take out the test cassette and lay
it on a clean flat surface, then mark the cassette with the patient ID or
sample number and add 4 drops (approximately 100 μL) of processed sample
extract into the sample well. The result should be observed within 15-20
minutes. Results observed after 20 minutes are invalid.
Test Method Limitations
- The accuracy of the test is dependent on the quality of the sample. Improper sampling or storage, using expired samples or repeated frozen-thawed samples can affect the test result. Test results can also be affected by temperature and humidity.
- Negative results may be caused by low concentration of SARS-CoV-2 antigens in the sample and therefore cannot completely rule out the possibility of infection.
- Some medication (e.g. high concentration of over-the-counter (OTC) or prescription medication such as nasal spray) in the collected samples may interfere with the test result. Please perform the test again if the result is in doubt.
- This product is only for qualitative testing and the specific concentration of each indicator must be measured using other quantitative methodologies.
- The results of this test are for clinical reference only and should not be the only basis for diagnosis. Results should be used in combination with clinical observations and other testing methods.
Display of Results/Expected Values
- Negative result: If only the quality control C line appears and the detection T line is not visible, the sample contains no SARS-CoV-2 antigens or the concentration of the SARS-CoV-2 antigen is lower than the limit of detection and the result is negative.
- Positive result: If both the quality control Cline and the detection T line appear, then the SARS-CoV-2 antigens have been detected and the result is positive.
- Invalid result: If the Cline does not appear, the result is invalid and a new test must be performed.
Note: The color intensity of the T line is related to the concentration of SARS-CoV-2 antigens contained in the sample, and the result should be determined by whether the T line is colored or not regardless of the color intensity.
External Positive and Negative Controls
Good laboratory practice suggests the use of positive and negative controls to
ensure that test kits are working and that the test is correctly performed.
Only one red-colored Cline in the observation window can be seen while using a
negative quality control swab. Both red-colored C line and T line in the
observation window can be seen while using a positive quality control swab. If
the correct control results are not obtained, do not perform patient tests or
report patient results. Contact your local vendor or Medomics during normal
business hours before testing patient specimens. Please refer to the
Instructions For Use of Medomics SARS-CoV-2 antigen test kit (LFIA) External
control swab kit for expected test results and other information.
Ordering And Contact Information
Reference Numbers:
- Type:IV: SARS-CoV-2 antigen test kit (LFIA) External control swab kit (1test /kit),
- Type:V: SARS-CoV-2 antigen test kit (LFIA) External control swab kit (10 tests /kit)
If necessary, please contact your local vendor or Jiangsu Medomics Medical Technology Co. Ltd Technical Services at (+86)025-58601060/ (+86)025-58601213 and email (info@medomics-dx.com )
Product Performance
-
High Dose Hook Effect
No hook effect was observed with the SARS-CoV-2 virus up to a concentration of 1.0 x 10 TCID50/mL. -
Limit of Detection – LoD
Limit of Detection (LoD) studies determined the lowest detectable concentration of SARS-CoV-2 at which 95% of all (true positive) replicates test positive. Dilute the SARS-CoV-2 wild type with lysis buˆer to an ÿnal concentration gradient of 5, 10, 50, 100, 200, 1000 TCID50/mL.ild type with lysis bu er to a final concentration gradient of 5, 10, 50, 100, 200, 1000 TCID50| /mL.
---|---
SARS-CoV-2 wild type tested (TCID50/mL)| Test Result
1000| 20/20 positive
200| 20/20 positive
100| 20/20 positive
50| 20/20 positive
10| 20/20 positive
5| 12/20 positive -
Veriÿcation of Variants
SARS-CoV-2 antigen Test Kit(LFIA) can detect the recombinant nucleocapsid antigens of SARS-CoV-2 variants listed below.WHO label| Alpha| Beta| Gamma| Kappa| Delta| Lota| Epsilon
---|---|---|---|---|---|---|---
Pango lineage| B.1.1.7| B.1.351| P.1| B.1.617.1| B.1.617.2| B.1.526| B.1.427/B.1.429 -
Cross-Reactivity
Cross-reactivity and potential interference of Medomics SARS-CoV-2 antigen Test Kit (LFIA) were evaluated by testing commensal and pathogenic microorganisms diluted with nasal swabs as sample matrix in the absence or presence of heat-inactivated SARS-CoV-2 virus. The listed items in the following table may be present in the clinical samples. Each of the bacterium, viruses, and yeast was tested in triplicate with no false-positive results.Potential Cross-Reactant| Concentration Tested| Cross-Reactivity (Yes/No)
---|---|---
Human coronavirus 229E| 1.0 x 105 TCID50/mL| No
Human coronavirus OC43| 1.0 x 105 TCID50/mL| No
Human coronavirus NL63| 1.0 x 105 TCID50/mL| No
Human coronavirus HKU1| 1.0 x 105 TCID50/mL| No
MERS-coronavirus| 1.0 x 105 TCID50/mL| No
SARS-coronavirus| 1.0 x 105 TCID50/mL| No
Inuuenza A H1N1| 1.0 x 105 TCID50/mL| No
Inuuenza A H3N2| 1.0 x 105 TCID50/mL| No
Inuuenza A H5N1| 1.0 x 105 TCID50/mL| No
Inuuenza A H7N9| 1.0 x 105 TCID50/mL| No
Inuuenza B Victoria| 1.0 x 105 TCID50/mL| No
Inuuenza B Yamagata| 1.0 x 105 TCID50/mL| No
Parainuuenza virus Type 1| 1.0 x 105 TCID50/mL| No
Respiratory syncytial virus| 1.0 x 105 TCID50/mL| No
Enterovirus CA16e| 1.0 x 105 TCID50/mL| No
Adenovirus| 1.0 x 105 TCID50/mL| No
Mycoplasma pneumoniae| 1.0 x 106 CFU/mL| No
Staphylococcus aureus| 1.0 x 106 CFU/mL| No
Staphylococcus epidermidis| 1.0 x 106 CFU/mL| No
Bordetella pertussis| 1.0 x 106 CFU/mL| No
Legionella pneumophila| 1.0 x 106 CFU/mL| No
Streptococcus pneumoniae| 1.0 x 106 CFU/mL| No
Haemophilus influenzae| 1.0 x 106 CFU/mL| No
Mycobacterium tuberculosis| 1.0 x 106 CFU/mL| No
Candida albicans| 1.0 x 106 CFU/mL| No -
Precision
Precision performance is determined by a precision test that uses a negative enterprise reference sample and two positive enterprise samples (weak positive and strong positive). The variability such as operator, days, assay runs, and different batches were covered in the test.
| Negative | Weak Positive | Strong Positive |
|---|---|---|
| 100% | 97.08% | 100% |
- Interfering Substances Effect
The interfering substance tests conducted include but are not limited to the following interfering substances required by the WHO.Substance| Potential Interfering Substances| Concentration| Interference (Yes/No)
---|---|---|---
Endogenous Substance
| Mucin| 2 % w/v| No
Whole Blood| 5 % v/v| No
Human Anti-mouse Antibody(HAMA)| 200 IU/ml| No
Exogenous Substance
|
Nasal spray or
nasal drops
| Phenylephrine hydrochloride| 15 % v/v| No
Oxymetazolin hydrochloride| 15 % v/v| No
Sodium chloride with preservatives| 4.44 mg/mL| No
Nasal cortieosteroid
| Beclomethasone| 4.79 ng/mL| No
Dexamethasone| 0.8 mg/mL| No
Flunisolide| 0.61 µg/mL| No
Triamcinolone| 0.8 mg/mL| No
Budesonide| 0.5 mg/mL| No
Fluticasone Propionate| 5 % w/v| No
Throat Lozenge| Benzocaine| 0.13 mg/mL| No
Antibiotic| Mupirocin| 0.25 % w/v| No
Anti-Anti drugs| Tamiuu (Oseltamivir Phosphate)| 0.5 % w/v| No
Antibacterial| Tobramycin| 24.03 µg/mL| No
Biotin| Biotin| 1.2 µg/mL| No
- Clinical Performance
The performance of the Medomics SARS-CoV-2 antigen Test Kit(LFIA) was established with 363 Nasopharyngeal swabs collected from patients with COVID-19 symptoms within 7 days after the onset of symptoms. Clinical samples were evaluated to be positive or negative using FDA EUA RT-PCR reference methods. Two copies of samples were collected from one patient. One copy was tested directly using Medomics SARS-CoV-2 antigen Test Kit(LFIA) and the other was tested by RT-PCR The results are summarized in the following:
Table 1: Medomics Results from Patients and PCR (Nasopharyngeal secretion
RT-PCR
Medomics Ag test| Positive| Negative| Total
Positive| 133| 0| 133
Negative| 1| 229| 230
Total| 134| 229| 363
Sensitivity: 99.25% (95.91%-99.98%) PPV: 100% (97.26%-100%)
Specificity: 100% (98.40%-100%) NPV: 99.57% (97.60%-99.99%)
Accuracy: 99.72% (98.47%-99.99%)
Table 2：Sensitivity by CT values (Nasopharyngeal secretion)
CT value|
Quantity of PCR Test Results
|
Quantity of Medomics Antigen Test Results
| % Positive
---|---|---|---
Ct ≤25| 89| 89| 100%
25<Ct≤30| 43| 43| 100%
30<Ct≤33| 2| 1| 50%
Total| 134| 133| 99.25%
Table 3：Sensitivity by Days after symptom onset (Nasopharyngeal secretion)
Days after symptom onset| Quantity of PCR Test Results| Quantity of Medomics
Antigen Test Results| % Positive
---|---|---|---
0| 13| 13| 100%
1| 13| 13| 100%
2| 28| 28| 100%
3| 16| 16| 100%
4| 24| 24| 100%
5| 28| 28| 100%
6| 10| 9| 90%
7| 11| 11| 100%
Total Subjects| 143|
The performance of the Medomics SARS-CoV-2 antigen Test Kit(LFIA) was established with 264 Throat swabs collected from patients with COVID-19 symptoms within 7 days after the onset of symptoms. Clinical samples were evaluated to be positive or negative using FDA EUA RT-PCR reference methods. Two copies of samples were collected from one patient. One copy was tested directly using Medomics SARS-CoV-2 antigen Test Kit(LFIA) and the other was tested by RT-PCR The results are summarized in the following:
Table 4: Medomics Results from Patients and PCR (Throat secretion)
RT-PCR
Medomics COVID-19 Ag test| Positive| Negative| Total
Positive| 83| 2| 85
Negative| 4| 175| 179
Total| 87| 177| 264
Sensitivity: 95.40% (88.64%-98.73%) PPV: 97.65% (91.76%-99.71%)
Specificity: 98.87% (95.98%-99.86%) NPV: 97.77% (94.38%-99.39%)
Accuracy: 97.73% (95.12%-99.16%)
Table5: Sensitivity by CT values (Throat secretion)
CT value|
Quantity of PCR Test Results
|
Quantity of Medomics Antigen Test Results
| % Positive
---|---|---|---
Ct ≤25| 42| 41| 97.62%
25<Ct≤30| 43| 41| 95.35%
30<Ct≤33| 2| 1| 50%
Total| 87| 83| 95.40%
Table 6: Sensitivity by Days after symptom onset (Throat secretion)
Days after symptom onset| Quantity of PCR Test Results| Quantity of Medomics
Antigen Test Results| % Positive
---|---|---|---
0| 8| 7| 87.5%
1| 7| 7| 100%
2| 18| 18| 100%
3| 14| 14| 100%
4| 18| 16| 88.89%
5| 21| 20| 95.24%
6| 4| 4| 100%
7| 7| 7| 100%
Total Subjects| 97|
The performance of the Medomics SARS-CoV-2 antigen Test Kit(LFIA) was established with 216 Anterior nasal swabs collected from patients with COVID-19 symptoms within 7 days after the onset of symptoms. Clinical samples were evaluated to be positive or negative using FDA EUA RT-PCR reference methods. Two copies of samples were collected from one patient. One copy was tested directly using Medomics SARS-CoV-2 antigen Test Kit(LFIA) and the other was tested by RT-PCR The results are summarized in the following:
Table 7: Medomics Results from Patients and PCR (Anterior nasal secretion)
RT-PCR
Medomics COVID-19 Ag test| Positive| Negative| Total
Positive| 107| 1| 108
Negative| 5| 103| 108
Total| 112| 104| 216
Sensitivity: 95.54% (89.89%-98.53%) PPV: 99.07% (94.95%-99.98%)
Specificity: 99.04% (94.76%-99.98%) NPV: 95.37% (89.53%-98.48%)
Accuracy: 97.22% (94.05%-98.97%)
Table8: Sensitivity by CT values (Anterior nasal secretion)
CT value|
Quantity of PCR Test Results
|
Quantity of Medomics Antigen Test Results
| % Positive
---|---|---|---
Ct ≤25| 64| 63| 98.44%
25<Ct≤30| 43| 42| 97.67%
30<Ct≤33| 5| 2| 40%
Total| 112| 107| 95.54%
Table 9: Sensitivity by Days after symptom onset (Anterior nasal secretion)
Days after symptom onset| Quantity of PCR Test Results| Quantity of Medomics
Antigen Test Results| % Positive
---|---|---|---
0| 10| 10| 100%
1| 8| 7| 87.5%
2| 17| 17| 100%
3| 14| 14| 100%
4| 22| 20| 90.91%
5| 17| 16| 94.12%
6| 6| 6| 100%
7| 9| 9| 100%
Total Subjects| 103|
[References]
- | LY Wang, PR Chen, GW Zheng, et al. Research progress on novel coronavirus test methods. Modern Medicine and Clinic, 2020, 35(3): 411-416.
- | K Tugba, W Ralph, L Hakho. Molecular and Immunological Diagnostic Tests of COVID-19: Current Status and Challenges. science, 2020, 23 (8): Doi: 10.1016/j.is-ci.2020.101406
Sponsor
JENINNO SOLUTIONS PTY LTD UNIT 605, 12 ALBERT STREET, HAWTHORN EAST, VIC, 3123 info@jeninnosolutions.com.au
Jiangsu Medomics Medical Technology Co., Ltd. F3, BuildingC, No.3-1
XinjinhuRoad, Jiangbei New Area, Nanjing, Jiangsu, China.
Tel: (+86)025-58601060/ (+86)025-58601213
Fax: 025-58601060 E-mail: info@medomics-dx.com