GA-CoV-2 ELISA diagnostic workflow includes 3 screens for all immunodominant proteins of SARS-CoV-2 (N, S1, S2) achieving an overall specificity of 99%. The round of the screening includes both IgM and IgG with a sensitivity of 98% ten days post infection.
The GA CoV-2 IgG+ confirmatory test offers reliable support to differentiate other coronavirus infections and aids in the assessment of immune protection. Following a positive antibody result in screening, virus-specific antibodies against the N, S1 and S2 proteins are determined using this confirmatory test. It is known that antibodies to the nucleocapsid (N) protein, may have been generated during a previous SARS or MERS infection. By confirming double positivity, and the confirmation of S1 or S2 antibodies specifically, we increased the specificity in our clinical trial to 99%.
Product Name: GA CoV-2 IgG+ EIA Intended Use: Module based Enzyme Immunoassay for the confirmation of positive IgG antibodies against SARS-CoV-2 in the first screening. The test determines the specificity of antibodies against the main immunodominant antigens (Spike Glycoprotein1, Spike Glycoprotein 2, Nucleocapsid) of SARS-CoV2 in human serum or plasma. Sample Type: Human Serum or Plasma Specificity: 95% Sensitivity: >98% Shelf life: 15 months Total assay time: 105 minutes Regulatory/Restrictions: For in-vitro Diagnostic Use Only
IgG confirmatory test specific for SARS CoV-2 N-, S1- and S2- proteins 24×4 determinations per test kit including positive and negative controls Fully automatable CE-IVD certified
Storage: This test kit must be stored at 2 – 8°C upon receipt. For the expiration date of the kit refer to the label on the kit box. All components are stable until this expiration date.
GA CoV-2 IgG + is a reagent kit for the determination of IgG antibodies against immunodominant major antigens of the SARS coronavirus-2. The test kit consists of modules separately coated with the major antigens of the virus:
The patient samples are pipetted horizontally over the 4 strips of a module (e.g. A1+A2+A3+A4), any antibodies present react with the antigens bound to the solid phase in the first reaction step. Unbound sample components are removed by a wash step after 45 minutes incubation at 37°C. The bound IgG antibodies react specifically with anti-human-IgG conjugated to horseradish peroxidase (HRP). Within the incubation period of 45 min at 37°C, excessive conjugate is separated from the solid-phase immune complexes by the following wash step.
HRP converts the colorless substrate solution of 3,3’,5,5’-tetramethylbenzidine (TMB) added into a blue product. The enzyme reaction is stopped by dispensing an acidic solution into the wells after 15 min at room temperature (18-25°C) turning the solution from blue to yellow.
The optical density (OD) of the solution measured at 450 nm is directly proportional to the amount of specific antibodies bound.
Ensure that no fingerprints are present on the bottom of the microtiter plate before OD measurement. Fingerprints could lead to false positive results.
Patient sample dilution 1 + 20 (v/v) i.e 50 µl serum + 1000 µl sample diluent (C) after the addiction of the sample the color of the sample diluent (C) changes from olive green to dark blue
The samples are applied horizontally into 4 cavities of a module according to the pipetting scheme:
In case of use of the kit controls (P, N), those controls can replace two samples in the above scheme.
1. Bring all reagents and the required number of test cavities to room temperature (18-25 °C) before use. Mix gently without causing foam. 2. Dispense into 4 horizontal wells of one module: 200 µl diluted samples. alternatively 200 µl of Negative control (N) and Positive control (P) instead of 2 samples 3. Add 50 µl of Start reagent (G) to all wells. 4. Cover plate, shake for 30 seconds, incubate 45 minutes at 37 °C. 5. Decant, then wash each well 5 times using 350 µl wash solution (made of B), use a soak time of 20 seconds each. 6. Add 100 µl of conjugate (D) solution to all wells. 7. Cover plate, incubate 45 minutes at 37 °C. 8. Repeat wash step 5. 9. Add 100 µl of substrate (E) to each well. 10. Incubate 15 min protected from light at room temperature (18…25 °C). 11. Add 100 µl of stop solution (F) to each well and mix gently. 12. Read the OD at 450 nm versus 620 (630 nm) within 20 min after adding the stop solution.
If the washing process cannot be carried out with a soak time of the washing buffer, the washing process must be extended by one step.
The test results are evaluated by calculating a cut-off from the mean value of the Negative control row (well N).
Cut-off (Co) = 0.250 + OD well N
The binding index BI is calculated by the ratio of OD values of samples to the Cut-off:
BI = OD sample / Co
Interpretation is done according to the following table:
Patients with borderline results should be retested after a period of 1-2 weeks using a freshly collected sample.
A confidence index of the confirmation test defines the degree of reliability of the given result and is listed in the table below:
This index is under further evaluation for “low” interpretation. A low index does not mean that the patient is negative and antibodies are not confirmed.
The test run is valid if:
OD 450/620 nm of Negative control < 0.200
OD 450/620 nm of Positive control > 0.500
OD 450/620 nm of row N < 0.250
If the above mentioned quality criteria are not met, repeat the test and make sure that the procedure is followed correctly (incubation times and temperatures, sample and wash buffer dilution, wash steps etc.). In case of repeated failure of the quality criteria contact your supplier.
Corona Virus Disease 2019 (COVID-19) is caused by the SARS-associated coronavirus 2 (SARS-CoV-2), which was first identified in a respiratory disease outbreak in Wuhan City, Hubei Province, China. It has since been responsible for a global pandemic. SARS-CoV-2 is a single-stranded RNA virus with positive polarity and belongs to the genus of beta-coronaviruses, which also includes SARS CoV (2003) and MERS CoV (2012). Like all other corona viruses, the genome of SARS CoV-2 (2019-nCoV) encodes the spike protein, the envelope protein, the membrane protein and the nucleocapsid protein.
ELISA kits for COVID-19 diagnostics
COVID-19 positive patients display a variety of symptoms with a large range of severity. Current research guidance suggests the length of time from initial infection with SARS-CoV-2 and appearance of first symptoms can be up to 14 days. RT-qPCR tests performed in hospital to confirm diagnosis in acute patients. This type of test examines the genetic material of the virus and give a positive result only if the virus is still present at a critical level. The tests are unable to identify individuals who have recovered.
The GA CoV-2 ELISA kits are serological tests that identify virus-specific antibodies in patients both during and post infection. Understanding the level of population exposure to SARS-CoV-2 and the number of recovered patients is key to a resilient pandemic response. Our simple GA CoV-2 Two Step ELISA confirms active cases and can indicate the level of immune protection following recovery by specifically identifying the IgG response to N-, S1- and S2- proteins are determined using GA CoV-2 IgG+ EIA confirmatory test.