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: Enzyme Immunoassay for the determination of IgG antibodies to SARS-Coronavirus 2 (SARS-CoV-2) in human plasma and serum for the monitoring of immune response in COVID-19 disease. Sample Type: Blood, Serum or Plasma Overall specificity: > 99% Sensitivity: ~ 98% Shelf life: 15 months Total assay time: 105 minutes Regulatory/Restrictions: For in-vitro Diagnostic Use Only.
ELISA screening for the determination of IgG SARS CoV-2 antibodies in serum and plasma. Reliable support to differentiate other coronavirus infections and aids in the assessment of immune protection. 96 determinations per test kit including positive and negative controls. Fully automatable. CE-IVD certified.
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 used for the determination of IgG antibodies to SARS Coronavirus-2.
Antibodies of the controls and diluted patient samples react with antigens immobilized on the solid phase of microtiter plates. Use of recombinant antigens guarantees the specific binding of autoimmune antibodies of the specimen under investigation. Following an incubation period of 45 min at 37°C, unbound sample components are removed by a wash step.
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.
Specimen collection and storage
Blood is taken by venipuncture. Serum is separated after clotting by centrifugation. Plasma samples (citrate, EDTA, heparin) can be used too, too. Hyperlipemic, hemolytic or contaminated samples must not be used and the samples must not contain preservatives.
Samples can be stored up to 5 days at 2 – 8 °C in the primary tubes. For longer storage, sera or plasmas extracted from the primary tubes must be frozen at -20°C. Repeated freezing and thawing should be avoided. If necessary, aliquots should be prepared before freezing.
Samples are diluted during the test, controls should not be diluted.
Ensure that no fingerprints are present on the bottom of the microtiter plate before OD measurement. Fingerprints could lead to false positive results.
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. Leave the first well empty for BLANK. Dispense into the respective wells: 200 µl Negative control (N) in triplicate 200 µl Positive control (P) 200 µl Sample diluent (C) into all patient wells. Add 10 µl of patient samples to the patient wells. Colour of sample diluent is turning to dark blueish green. 3. Dispense 50 µl of Start reagent (G) into all wells except BLANK. 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 except BLANK. 7. Cover plate, incubate 45 min at 37 °C. 8. Repeat wash step 5. 9. Add 100 µl of substrate (E) to each well including BLANK. 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.
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.