Rapid Coronavirus Antigen Test Kit

In June 2020, JOYSBIO Biotechnology proudly launched a new rapid COVID-19 antigen (colloidal gold) test kit. The new coronavirus antigen test kit is a lateral flow immunoassay for the qualitative detection of SARS-COV-2 (nucleocapsid protein) antigen in samples from the upper respiratory tract with nasal swabs or saliva during the acute phase of the infection. An uncut sheet format is available.

Characteristics

• 15-minute rapid detection
• Easy to operate coronavirus antigen test
• Less invasive nasal swab (NS) sample collection
• CE-IVD marking
• Available in 1/2/5/20 tests/box
• Versions available with nasopharyngeal swab and saliva

Presentation features

The JOYSBIO coronavirus Ag test kit was independently evaluated at Centro Diagnostico Delta S.r.l. in Italy between October 2020 and January 2021. A total of 107 positive samples were tested with the JOYSBIO COVID-19 Rapid Antigen Test Kit. These samples were obtained from patients with suspected COVID-19 with nasal swabs.

The sensitivity and specificity of the coronavirus antigen test kit are compared to a CE-IVD-marked RT-PCR test kit. This clinical evaluation is done under the assumption that SARS-CoV is no longer spreading in the community. Based on the clinical analysis of 492 samples, the detection sensitivity is 98.13% and the specificity is 99.22%.

• Positive Percentage Agreement (PPA) = 105/107 (98.13%) (95% CI: 93.4% ~ 99.8%)
• Negative Percentage Agreement (NPA) = 382/385 (99.22%) (95% CI: 97.7% ~ 99.8%)
• Accuracy = (105 + 382) /492tz100%=98.98%
• Kappa = 2 × (105 × 382-3 × 2) / (108 × 385 + 107 × 384) = 0.97 ＞ 0.5

Rapid COVID-19 Antigen Test Principle

The rapid coronavirus antigen test kit is a lateral flow assay that qualitatively detects the presence of nucleocapsid protein (N) in samples from the upper respiratory tract (nasal swabs). This lateral flow assay is designed with the sandwich immunoassay format. When the sample is added to the sample pad of a test cassette, the coronavirus protein N binds with the colloidal gold-labelled SARS-CoV-2 N protein antibody to form an antibody-antigen complex (Ab -Ag).

The Ab-Ag complex is captured by the SARS-CoV-2 N protein antibody (rabbit monoclonal antibody) when it migrates to the test line under capillary action. A red band will appear on the test line, indicating that the sample is positive for the nucleocapsid protein COVID-19. No coloured band will appear on the test line if the sample does not contain any coronavirus antigen (protein N) or if the antigen level is below the detection limit.

The conjugation pad also contains colloidal gold-labelled chicken IgY, which is captured by goat anti-chicken IgY in the control line as procedural control. A coloured band on the control line represents the proper liquid flow through the cassette; the absence of a coloured band in the control line indicates insufficient sample or buffer volume.

COVID-19 Antigen Test Procedure

• Twist the cap of the buffer bottle, carefully dispense all of the buffers into the extraction tube。
• After collecting the sample from the upper respiratory tract with a nasal swab, insert the swab into the collection tube, dip the swab up and down into the liquid for a minimum of 10 seconds. Hold the swab against the bottom of the tube, turn three turns. DO NOT splash liquid from the tube.
• Remove the swab while squeezing the sides of the tube to extract the liquid from the swab.
• Press the mouthpiece cap firmly onto the extraction tube. Mix well by twisting or shaking the bottom of the tube.
• Gently squeeze the rigid body of the tube, dispense two (2) drops of the buffer-sample mixture into the sample well in the coronavirus antigen test cassette.
• Read the test results in 15-20 minutes. Do not read the results after 20 minutes.

Interpretation of test results

Negative: A colour band appears on the control line (line C); no colour band appears on the test line (T line). A negative result indicates that there is no coronavirus antigen (protein N) in the sample or that the coronavirus antigen level is below the limit of detection.

Positive: One colour band appears on the control line (line C), a second colour band appears on the test line (line T). A positive result indicates the presence of COVID-19 antigen (protein N) in the patient sample.

Invalid: No colour band appears on the control line (line C). An invalid test result suggests that there may be insufficient buffer volume or incorrect operating procedures. Please review the testing procedure carefully and retest the same patient with another rapid coronavirus antigen test cassette. Contact your dealer if the problem persists.