Facts about testing for antibodies in connection with SARS-CoV-2

Overview:

  • Rapid: result in 15 minutes
  • 3 simple steps: add sample, add buffer, read results
  • Works with plasma, serum and whole blood
  • IgG: Sensitivity 100%, Specificity: 98.0%, Accuracy: 98.6%
  • IgM: Sensitivity 85.0%, Specificity: 96.0%, Accuracy: 92.9%
  • No cross-reactivity with influenza A & B, RSV, Adenovirus, HBsAg, Syphilis, H. Pylori, HIV & HCV
  • CE-IVD certified
  • Only for use by health care professionals

Rapid cassette-based test for SARS-CoV-2 Coronavirus

The Rapid POC (Point-of-Care) kit is a qualitative test that detects antibodies against 2019 nCoV in blood, serum or plasma. After applying the sample, antibodies bind to COVID antigen-coated particles in the test cassette. The mixture then moves chromatographically through the membrane. In the IgG or IgM test line region, it reacts with locally bound anti-human IgG or igM, respectively, resulting in a colored line.

If the specimen does not contain COVID-19 antibodies, no colored line will appear in any of the test line areas, indicating a negative result. As a positive control for the correct performance of the procedure and operation of the cassette, a colored line should always appear in the control line area. If the control line area is blank the test is invalid.

IgM type antibodies are generally the first to rise in response to viral infections. This is followed by high-affinity IgG, which remains in the bloodstream much longer. Therefore, testing for both IgM and IgG can give an indication of the stage of infection:

  • IgM only: early stage
  • IgM and IgG: mid stage
  • IgG only: late stage

Sensitivity and Specificity

The 2019-nCoV IgG/IgM Rapid Test Cassette was compared with a leading commercial PCR. The results show that 2019-nCoV IgG/IgM Rapid Test Cassette has a high sensitivity and specificity.

IgG result

  • Relative Sensitivity: 100% (86.0%-100%)*
  • Relative Specificity: 98.0% (89.4%-99.9%)*
  • Accuracy: 98.6% (92.3%-99.96%)*

IgM result

  • Relative Sensitivity: 85.0% (62.1%-96.8%)
  • Relative Specificity: 96.0% (86.3%-99.5%)
  • Accuracy: 92.9% (84.1%-97.6%)

* 95% confidence interval

Disclaimer and use limitations

  • The COVID-19 IgG/IgM Point-of-Care test is for in vitro diagnostic use by healthcare professionals only.
  • Before accepting orders buyer has to sign a disclaimer form to accept the special terms & conditions for use of this product.
  • This assay is suitable for the detection of IgG and IgM antibodies up to 2019 nCoV in whole blood, serum or plasma samples. Neither the quantitative value nor the increase in the concentration of IgG or IgM antibodies against 2019 nCoV can be determined by this qualitative test.
  • The COVID-19 IgG/IgM Point-of-Care test only indicates the presence of IgG and IgM antibodies to 2019 nCoV in the sample and should not be used as the sole criterion for the diagnosis of 2019 nCoV infections.
  • As with all diagnostic tests, all results should be considered with other clinical information available to the physician.
  • If the test result is negative and clinical symptoms persist, additional follow-up studies with other clinical methods are recommended. A negative result at any time does not rule out the possibility of COVID-19 infection.
  • The hematocrit level of the blood can affect the test results. The hematocrit level should be between 25% and 65% for accurate results.
  • The test will yield negative results under the following conditions: 1) The titer of the coronavirus antibodies in the sample is below the minimum detection limit of the test, or 2) the coronavirus antibody has not yet appeared at the time of sampling ( asymptomatic phase).