Sekbio Covid-19 Antibody LFA Uncut Sheet

Clinical Validation Result

Validated Product: COVID-19 antigen test (LFA) from SEKBIO Co., LTD.

Benchmark product: COVID-19 RT-PCR

Experiment 1: (Oropharyngeal swab eluted with matched sample extraction solution)

Number of samples	RT-PCR Results		SEKBIO COVID-19 antigen test result
Number of samples	CT values	Result	Result	Consistency
57	≤30	57 positives	57 positives	100%
82	≤33	82 positives	82 positives	100%
91	≤34	91 positives	90 positives	98.90%
149	≤36	149 positives	136 positives	91.28%
45	≥40	45 negatives	44 negatives	97.78%

Experiment 2 : (Nasopharyngeal swab/Oropharyngeal swab kept in UTM)

Number of samples	RT-PCR Results		SEKBIO COVID-19 antigen test result
Number of samples	CT values	Result	Result	Consistency
52	≤25.1	52 positives	52 positives	100%
82	≤34.8	82 positives	77 positives	93.9%
45	>40	45 negatives	45 negatives	100%

Clinical Validation Result

SARS-CoV-2 Antigen Rapid Test Strip Result

Performance Comparison Analysis SARS-CoV-2 Rapid Ag Test Uncut Sheet

Our Sars-Cov-2 antigen test can detect as low as 10 pg/ml

SARS-CoV-2 Antigen Rapid Test Strip Result

Test Report of the New Variants

1. Experiment purpose: The COVID-19 has produced a series of mutations during the pandemic. COVID-19 detection reagent (lateral flow chromatography) is now used to detect nucleocapsid protein (NP) recombinant proteins of variants from the UK, South Africa, the United States and Brazil, to verify the performance of the LFA assay on the variants.

2. Experiment materials

2.1. COVID-19 NP assay reagent (LFA), Batch No. 2101K402, the test results of NP recombinant protein was positive at 31.25pg/ mL and its result was weak positive at 20pg/mL.

2.2. NP recombinant protein of UK variant B.1.1.7, including mutation: D3L, S235F, expressed in HEK293 cell.

2.3. NP recombinant protein of South African variant B.1.351, including mutation: R203K, G204R, expressed in HEK293 cell.

2.4. NP recombinant protein of US variant B.1.2, including mutation: P67S, P199L, expressed in HEK293 cell.

2.5. NP recombinant protein of U Brazil variant B.1.1.28, including mutation: P80R, S235F, expressed in HEK293 cell.

3. Experiment method

3.1. The NP recombinant proteins of the four variants were diluted with sample diluent. The dilution ratio is as follows: 1/1K, 1/200K, 1/400K, 1/800K, 1/1600K, 1/3200K, 1/6400K, 1/12800K, 1/25800K

3.2. Use COVID-19 assay reagent (LFA) to detect the above diluted specimens. Each specimen is tested twice.

3.3. Add samples and interpret the results according to the operation methods in the instructions.

3.4. Record the results.

4. Experiment result

The experimental record results are shown as follows

Test Report of the New Variants

From the above table, the test result of NP recomb. protein of the UK variant was positive at dilution of 1/12800K and while it was slightly positive at dilution of 1/25600K. The test result of NP recombinant protein of the South African variant was positive at 1/6400K dilution and slightly positive at 1/12800K dilution, while it was negative at 1/25600K. The test result of NP recombinant protein of the American variant was positive at 1/3200K dilution and slightly positive at 1/6400K dilution, while it was negative at 1/12800K. The test result of NP recombinant protein of the Brazilian variant was positive at dilution of 1/6400K and slightly positive at dilution of 1/12800K, while it was negative at 1/25600K.

5. Experiment conclusion

The NP recombinant protein of the variant from the United Kingdom, South Africa, the United States and Brazil was detectable by the COVID-19 assay (LFA).

The NP recombinant protein of UK variant is detectable at the dilution ratio of 1/12800K.

The NP recombinant protein of US variant is detectable at the dilution ratio of 1/3200K.

The NP recombinant protein of Brazilian variant is detectable at the dilution ratio of 1/6400K.

The NP recombinant protein of South Africa variant is detectable at the dilution ratio of 1/6400K.

Test Report of the New Variants

Analysis of the potential Microbial cross-reaction

1 Experimental purpose

To investigate the impact of the test result of the novel coronavirus (SARS-CoV-2) antigen detection kit (colloidal gold immunochromatography) when coexisting other microorganisms in the sample.

2 Experimental materials

2.1 Novel coronavirus (SARS-CoV-2) antigen detection kit (colloidal gold immunochromatography)

2.2 Microbial cross-reaction samples (Detail in Table 1)

2.3 SARS-CoV-2 virus culture

Table 1

Sources	Sample No.	Sample Type
Chinese "National controls for SARS-CoV-2 antigen detection kit" N1~N20	N1	Staphylococcus aureus
	N2	Streptococcus pyogenes
	N3	Measles virus
	N4	Paramyxovirus parotitis
	N5	Adenovirus 3
	N6	Mycoplasma pneumoniae
	N7	Parainfluenza virus 2
	N8	Human Metapneumovirus (hMPV)
	N9	Human coronavirus OC43
	N10	Human coronavirus 229E
	N11	Bordetella parapertussia
	N12	Influenza B (Victoria strain)
	N13	Influenza B (Ystrain)
	N14	Influenza A (H1N1, 2009)
	N15	Influenza A (H3N2)
	N16	Avian influenza virus (H7N9)
	N17	Avian influenza virus (H5N1)
	N18	Epstein-Barr virus
	N19	Enterovirus CA16
	N20	Rhinovirus
Zhujiang Hospital of Southern Medical University	N21	Respiratory syncytial virus
	N22	Streptococcus pneumoniae
	N23	Candida albicans
	N24	Chlamydia pneumoniae
	N25	Bordetella pertussis
	N26	Human coronavirus NL63 (Recombinant protein)
	N27	Pneumocystis jirovecii
	N28	Mycobacterium tuberculosis
	N29	Human coronavirus HKU1 (Recombinant protein)
	N30	Legionella pneumophila

3 Experimental method

Add the SARS-Cov-2 virus culture to the specimens in 2.2, to make the concentration of the virus culture three times of the minimum detection limit (1.5×102 TCID50/mL). Use the prepared specimens as samples to test in accordance with the instructions. 3 repeats per specimen, record the results and analyze the data. The sample numbers are as follows:

Table 2 Added sample and its No.

Sources	Sample No.	Added sample	Sample type
Chinese "National controls for SARS-CoV-2 antigen detection kit" N1~N20	N1	N1+	Staphylococcus aureus
	N2	N2+	Streptococcus pyogenes
	N3	N3+	Measles virus
	N4	N4+	Paramyxovirus parotitis
	N5	N5+	Adenovirus 3
	N6	N6+	Mycoplasma pneumoniae
	N7	N7+	Parainfluenza virus 2
	N8	N8+	Human Metapneumovirus (hMPV)
	N9	N9+	Human coronavirus OC43
	N10	N10+	Human coronavirus 229E
	N11	N11+	Bordetella parapertussia
	N12	N12+	Influenza B (Victoria strain)
	N13	N13+	Influenza B (Ystrain)
	N14	N14+	Influenza A (H1N1, 2009)
	N15	N15+	Influenza A (H3N2)
	N16	N16+	Avian influenza virus (H7N9)
	N17	N17+	Avian influenza virus (H5N1)

	N18	N18+	Epstein-Barr virus
	N19	N19+	Enterovirus CA16
	N20	N20+	Rhinovirus
Zhujiang Hospital of Southern Medical University	N21	N21+	Respiratory syncytial virus
	N22	N22+	Streptococcus pneumoniae
	N23	N23+	Candida albicans
	N24	N24+	Chlamydia pneumoniae
	N25	N25+	Bordetella pertussis
	N26	N26+	Human coronavirus NL63（Recombinant protein）
	N27	N27+	Pneumocystis jirovecii
	N28	N28+	Mycobacterium tuberculosis
	N29	N29+	Human coronavirus HKU1( Recombinant protein）
	N30	N30+	Legionella pneumophila

4 Experimental results

Table 3 Test results of interference reaction

Original Sample	Result			Added Sample	Result
Original Sample	Batch 1	Batch 2	Batch 3	Added Sample	Batch 1	Batch 2	Batch 3
N1	-	-	-	N1+	+	+	+
N2	-	-	-	N2+	+	+	+
N3	-	-	-	N3+	+	+	+
N4	-	-	-	N4+	+	+	+
N5	-	-	-	N5+	+	+	+
N6	-	-	-	N6+	+	+	+
N7	-	-	-	N7+	+	+	+
N8	-	-	-	N8+	+	+	+
N9	-	-	-	N9+	+	+	+
N10	-	-	-	N10+	+	+	+
N11	-	-	-	N11+	+	+	+
N12	-	-	-	N12+	+	+	+
N13	-	-	-	N13+	+	+	+
N14	-	-	-	N14+	+	+	+
N15	-	-	-	N15+	+	+	+
N16	-	-	-	N16+	+	+	+
N17	-	-	-	N17+	+	+	+
N18	-	-	-	N18+	+	+	+

N19	-	-	-	N19+	+	+	+
N20	-	-	-	N20+	+	+	+
N21	-	-	-	N21+	+	+	+
N22	-	-	-	N22+	+	+	+
N23	-	-	-	N23+	+	+	+
N24	-	-	-	N24+	+	+	+
N25	-	-	-	N25+	+	+	+
N26	-	-	-	N26+	+	+	+
N27	-	-	-	N27+	+	+	+
N28	-	-	-	N28+	+	+	+
N29	-	-	-	N29+	+	+	+
N30	-	-	-	N30+	+	+	+

Note: "+" indicates a positive result, and "-" indicates a negative result.

5 Experimental conclusions

Cross-reaction experiments were conducted on three batches of reagents, and based on the results, the company’s novel coronavirus (SARS-CoV-2) antigen detection kit (colloidal gold immunochromatography) was used to detect the novel coronavirus (SARS-CoV-2). There are no false negatives and false positives for the specimens coexisting with other microorganisms. Therefore, the above microorganisms have no impact on the experimental results.

Analysis of the potential Microbial cross-reaction

Uncut sheet of COVID-19 antigen detection

Product Name

Uncut sheet of COVID-19 antigen detection

Novel coronavirus (SARS-CoV-2) antigen detection kit (colloidal gold immunochromatography)- detection membrane

Spec.

60mm*300mm

Lot No.

2011K401

Production

quantity

612 pieces

Sampling

Amount

8 pieces

Production

Date

2020-11-01

Exp.

2023-04

Store at

sealed at 2⁓30℃

Reported

2020-11-02

Inspection record

Test items

Acceptance Criteria

Result

Conclusion

Appearance

Clean, no scratches, smooth surface, no damage, no burrs, no stains;

Each support of the large board should be

firmly pasted.

☑ Meet the requirements

□ non-compliant

☑ qualified

□ Unqualified

Length

（mm）

300mm±3mm

300mm

☑ qualified

□ Unqualified

C line, T line position

T line，B position should be 30mm±0.5mm；

C line B position should be

34.5mm±0.5mm

T line, B position is：30.0mm C line, B position is：34.5mm

☑ qualified

□ Unqualified

Liquid moving speed

(mm/min)

≥10mm/min

57.5mm/min

☑ qualified

□ Unqualified

Fading time of film

（min）

15~20min

16min

☑ qualified

□ Unqualified

Positive rate of positive

reference

Use the corporate positive reference product P1-P5 to test, The result should meet the requirement as follows:

The color intensity of P1 should be C8-C7;

☑ Meet the requirements

□ non-compliant

☑ qualified

□ Unqualified

The color intensity of P2 should be C6~C5;

The color intensity of P3 should be C5~C4;

The color intensity of P4 should be C8~C7;

The color intensity of P5 should be

C7~C6.

Minimum detection limit

Use corporate lowest detection limit reference product L1⁓L3 for testing, the result should meet the requirement as follows:

The color intensity of L1 should be B;

The color intensity of L2 should be C9~C7; The color intensity of L3 should be C8~C7.

☑ Meet the requirements

□ non-compliant

☑ qualified

□ Unqualified

Precision

Use corporate repeatable reference product R1⁓R2 to test, and the result should meet the requirement as follows: The color intensity of R1 should be C6~C5;

The color intensity of R2 should be

C7~C6.

☑ Meet the requirements

□ non-compliant

☑ qualified

□ Unqualified

Negative rate of Negative

reference

Test corporate negative reference product N1⁓N7, all color intensity should be B.

☑ Meet the requirements

□ non-compliant

☑ qualified