About IgM/IgG Rapid Test
The COVID-19 Corona Virus IgM/IgG Rapid Test is an in vitro diagnostic test solely for the qualitative determination of COVID-19’s IgM and IgG antibodies in human whole blood, serum, plasma and fingertip blood.
The test kit is based on immunoassay technology. The test devices contain:
Conjugate pad: recombinant SARS-CoV-2 antigen labelled with colloidal gold and quality control antibody gold marker.
NC membrane: coated with two detection lines (IgG line and IgM line) and one quality control line (C line). The IgM line coated with mouse anti human IgM monoclonal antibody detects the COVID-19 Corona Virus IgM antibody. The IgG line coated with mouse anti-human IgG monoclonal antibody detects the COVID-19 Corona Virus IgG antibody. The C line coated with quality control antibody. When sample is added to the sample well of the test device, it will move forward along the test device. If the sample contains IgM antibodies, antibodies will bind to the virus antigen labelled with colloidal gold, then forms a sandwich complex with the coated anti-human IgM monoclonal antibody at IgM line, IgM line will appear purplish red, prompting the COVID-19 Corona Virus IgM antibody is positive. If the sample contains IgG antibodies, antibodies will bind to the virus antigen labelled with colloidal gold, then forms a sandwich complex with the coated anti human IgG monoclonal antibody at IgG line, IgG line will appear purplish red, prompting the COVID-19 IgG antibody is positive. If either line IgG or IgM does not show colour, the negative result will be displayed. The test device also contains a quality control line C, whether there is a test line or not, quality control line C should display purplish red. Test result will be invalid if quality control line C does not show colour, this sample needs to be retested.
The Rapid Detection Kit is for professional use only and can be used in Centers for Disease Control and Prevention, Primary Health Care Institutions, Government Department / Public Institution State-Owned Enterprise / Large Company, Industrial Production Enterprise, Schools and/or Prison / Detention Center/ Drug Rehabilitation Center.
Disclaimer:
On March 16, 2020 the FDA updated its Policy for Diagnostic Tests for Coronavirus Disease-2019 during the Public Health Emergency. The updates include guidance for commercial manufacturers such as BioMedomics for serology test that identify antibodies (e.g., IgM, IgG) to sARS-CoV-2 from clinical specimens. The policy allows testing in laboratories or by healthcare workers at the point-of-care. The policy does not apply to at-home testing.
Laboratories and healthcare providers must include this information in their patient test report as specified in FDA guidance:
This test has not been reviewed by the FDA. The test has been validated but FDA's independent review of the test is pending.
Negative results do not rule out SARS-CoV-2 infection, particularly in those who have been in contact with the virus. Follow-up testing with a molecular diagnostic should be considered to rule out infection in these individuals.
Results from antibody testing should not be used as the sole basis to diagnose or exclude SARS-CoV-2 infection or to inform infection status.
Positive results may be due to past or present infection with non-SARS-CoV-2 coronavirus strains, such as coronavirus HKU1, NL63, OC43, or 229E.
How it Works
lgM and lgG are the first antibodies appearing in the human immune system during infection. Because of their high specificity, when detecting acute SARS-CoV-2 infection, lgM and lgG antibodies have the advantages of high sensitivity, early diagnosis, and the ability to judge whether a suspect is infected. lgM and lgG antibodies can only be produced after several days of viral infection and differ between individuals. IgM: Appear on day 1-7 of an acute infection. Detection of IgM in blood indicates a recent infection. It can be used as early screening for Novel CoV suspected population.IgG: In the mid to late stage of infection B lymphocytes enter lymph node and transform into plasma cells and produce large amount of IgG. Detection of IgG indicate on-going or past infection, useful in the monitoring of progress of infection.
Interpretation of Results
Positive result:
1. The COVID-19 Corona Virus IgM antibody is detected if the quality control line C and the detection line IgM are both coloured, and the detection IgG line is not coloured, that means the COVID-19 IgM antibody is positive.
2. The COVID-19 Corona Virus IgG antibody is detected if the quality control line C and the detection IgG line are both coloured, and the detection IgM line is not coloured, that means the COVID-19 IgG antibody is positive.
3. The COVID-19 Corona Virus IgG and IgM antibodies are detected if the quality control line C, the detection line IgM and IgG are both coloured, that means both the COVID-19 IgG and IgM antibodies are positive.
Negative result:
If there is only quality control line C is coloured, IgG and IgM detection lines are not coloured, the COVID-19 Corona Virus IgM/IgG antibody is not detected, that means the result is negative.
Invalid result:
If the quality control line C is not coloured, no matter whether the detection line IgG/IgM is coloured or not, the result is invalid and needs to be tested again.