New coronavirus reagent

[Product name]

Generic name: Novel Coronavirus (COVID-19) IgM/IgG Antibody Detection Kit (Quantum Dot-based Fluorescence Immunochromatography)English name: Novel Coronavirus (COVID-19) IgM/IgG Antibody Detection Kit (Quantum Dot-based Fluorescence Immunochromatography)

[Package specifications] 20 tests/kit, 100 tests/kit

[Intended use]

It is used for rapid qualitative detection of novel coronavirus (COVID-19) IgM/IgG antibodies in human whole blood, plasma or serum samples for screening and auxiliary diagnosis of clinical infection or suspected patients.

[Test principle]

This kit uses capture quantum dot-based fluorescence immunochromatography to detect IgM/IgG antibodies against novel coronavirus. Binding pads are prepared by using recombinant novel coronavirus S1 antigen labeled quantum dot-based microspheres, and the nitrocellulosic membranes are coated with anti-human IgG (T1), anti-human IgM (T2) and anti-novel coronavirus S1 antibodies (C-line). If new coronavirus antibodies (IgG/IgM) are present in the samples to be tested, they are specifically bound to S1 antigen labeled on quantum dot-based microspheres through the binding pad, and then respectively captured by anti-human IgG and/or anti-human IgM during the process of passing through nitrocellulose membrane, forming immune sandwich complexes at T1/ T2 positions respectively. The redundant quantum dot-based antigen binding complex is captured by the S1 antibody on the C-line and is fixed on the C-line. The captured quantum dot-based microspheres can generate red fluorescence signals under the irradiation of ultraviolet light.

[Main components]

Note: do not mix different batches of reagents.

[Storage conditions and expiry date] 

The kit should be kept dry and away from light under 4℃-30℃. Its period of validity is 24 months. 

[Applicable instruments] Ultraviolet flashlight, immunofluorescence analyzer

[Sample requirements]

① There are no special requirements for subjects before sample collection, and no fasting is required for subjects.

② Serum, plasma or fingertip blood is collected routinely.

③ Samples that have been heated or contaminated with microorganisms cannot be used for testing.

④ Samples should avoid repeated freezing-thawing as far as possible, and samples stored in low temperature should be balanced to room temperature before use and thoroughly mixed before testing.

[Test method]

① Get the test card from the aluminum foil bag and place it horizontally on the clean operating table.

② Take samples for test and add them into the sample wells of test card.

Serum or plasma samples: 10ul of sample is added to the sample well, and then 10ul of sample diluent is added (sample and sample diluent can be pre-mixed and then added to the sample well).

Fingertip blood sample: 1 drop of fingertip blood sample is directly dropped into the sample well, and then 3 drops of sample diluent are added.

③ Leave them at room temperature for 15 minutes and then observe the results, but the reading results after 30 minutes are invalid.

[Positive value or reference range] This kit is a qualitative reagent without reference value.

[Interpretation of test results]

Visual interpretation:

① Negative: Only one fluorescent line appears at the quality control line C on the test card,                 

indicating that the subject is not infected with the novel coronavirus or the body has not

produced relevant antibodies after the infection.

② Positive:  

.The detection card shows one fluorescence line at the detection line T2 and one at the quality              

control line C, which is positive for IgM antibody of novel coronavirus, indicating that the subject 

is at the early stage of infection of novel coronavirus.

.The detection card shows one fluorescence line at the detection line T1, one at the detection               

line T2, and one at the quality control line C, indicating that the subject is infected with novel                

Coronavirus, and both IgM and IgG antibodies are positive.

.The detection card shows one fluorescence at the detection line T1 and one at the quality control            

 line C, indicating that the subject is infected with novel coronavirus, and IgG antibody is 

positive.

③ Invalid: no fluorescence line appears on the detection card at the quality control line C, which is invalid. But for individual strong positive, fluorescence line may not appear at line C line.

Interpretation via machine:

 Fluorescence immunoanalyzer is used to measure, and instrument measurement value 100 is the cutoff value of IgG and IgM:

  ① When the measurement value of line C is ≥ 100, the detection result is valid; when the measurement value of line C is < 100, the detection result is invalid；

② When T1 and T2 measurements are ≤ 100, the results are negative；

③ IgG antibody is positive when T1 measurement ≥ 120 and T2 measurement < 120；

④ IgM antibody is positive when T2 measurement ≥ 120 and T1 measurement < 120；

⑤ Both IgG and IgM antibodies are positive when T1 and T2 values are ≥ 120；’

⑥ When the measured value is greater than 100 and less than 120, it is the gray area. Then the sample should be re-inspected or re-sampling for re-inspection..

Notes: 1. Instrument: dry fluorescent immunoanalyzer Model No.: FIC-S100 Registration Certificate No.: Su Machine Registration Permission 20172401387

2. Different instruments need to reset the cutoff value according to the reading conversion.

[Limitations of test methods]

① This kit only qualitatively detects IgM/IgG antibodies against novel coronavirus.

② This kit is a product of quantum dot-based fluorescence immunoassay, with inherent methodological limitations.

[Property indexes of product]

1 Appearance

There is no damage on the outer package of the kit and no stain on the detection card.

2 Performance testing

Use national reference or standardized enterprise reference for testing.

2.1 National reference of IgM antibody detection reagents 

2.1.1 Conformity rate of negative reference

Test with national negative reference, the results should meet the corresponding requirements.

2.1.2 Conformity rate of positive reference

Test with national positive reference, the results should meet the corresponding requirements.

2.1.3 Sensitivity

The national minimum test reference shall be used for testing and the results should meet the corresponding requirements.

2.1.4 Accuracy

The national precision reference is used for 10 parallel tests, and the results should all be positive with the same reaction intensity.

2.1.5 Difference between batches

Three different batches of reagents are taken, and each batch is tested in parallel with the national precision reference for 10 times. The results should all be positive with the same reaction intensity.

2.2 National reference for IgG antibody detection reagents

2.2.1 Conformity rate of negative reference

Test with national negative reference, the results should meet the corresponding requirements.

2.2.2 Conformity rate of positive reference

Test with national positive reference, the results should meet the corresponding requirements.

2.2.3 Sensitivity

The national minimum test reference shall be used for testing and the results should meet the corresponding requirements.

2.2.4 Accuracy

The national precision reference is used for 10 parallel tests, and the results should all be positive with the same reaction intensity.

2.2.5 Difference between batches

Three different batches of reagents are taken, and each batch is tested in parallel with the national precision reference for 10 times. The results should all be positive with the same reaction intensity.

2.3 Enterprise reference

2.3.1 Conformity rate of negative reference

Conformity rate of negative reference should be 10/10.

2.3.2 Conformity rate of positive reference

Conformity rate of negative reference should be 10/10.

2.3.3 Sensitivity

L1 and L2 should be detected，L3 may or may not be detected，L4 should not be detected.

2.3.4 Accuracy

Use 10 detection cards of the same batch to test precision reference, and the results should be all positive.

2.3.5 Difference between batches

Take three different batches and 10 test cards for each batch, test the same precision reference and the results should be positive.

[Attentions]

① This test card is only used for diagnosis in vitro, and the new coronavirus antibodies in blood samples are qualitatively detected.

② The diluent should be added immediately after the sample to be measured is added into the sample well. The interval time should not be too long.

③ Strictly follow the test method in the instructions, observe and judge the reaction results within the required time.

④ When using different testing instruments, one should read the instructions carefully, operate and interpret the results in accordance with the equipment operating instructions strictly.

⑤ All samples tested should be treated as infectious materials.

⑥ The kit kept refrigerated should be balanced to room temperature before the test, otherwise it will affect the test results.

⑦ Using ultraviolet flashlight to observe the results, one should be equipped with anti-ultraviolet glasses and do a good job of protection.

[References] 

①Lee, S.; Mehta, S.; Erickson, D., Two-Color Lateral Flow Assay for Multiplex Detection of Causative Agents      

Behind Acute Febrile Illnesses. Anal Chem 2016, 88 (17), 8359-63.

②Wang, R.; Ongagna-Yhombi, S. Y.; Lu, Z.; Centeno-Tablante, E.; Colt, S.; Cao, X.; Ren, Y.; Cardenas, W. B.;

Mehta, S.; Erickson, D., Rapid Diagnostic Platform for Colorimetric Differential Detection of Dengue and

Chikungunya Viral Infections. Anal Chem 2019, 91 (8), 5415-5423.

③Rong, Z.; Wang, Q.; Sun, N.; Jia, X.; Wang, K.; Xiao, R.; Wang, S., Smartphone-based fluorescent lateral flow

immunoassay platform for highly sensitive point-of-care detection of Zika virus nonstructural protein 1.

Anal. Chim. Acta 2019, 1055, 140-147.

SARS-CoV-2 Antibody Test_Lepu Medical.pdf