recomLine SARS-CoV-2 IgG [Avidity]
RESEARCH USE ONLY!
2 Field of application
The recomLine SARS-CoV-2 IgG [Avidität] is a line immunoassay. The separate line-up of individual antigens means that, unlike ELISA, the test allows identification of specific antibodies against the individual an- tigens of the various coronaviruses. The test uses for SARS-CoV-2 (severe acute respiratory syndrome Coronavirus 2) the following re- combinant antigens: NP (nucleocapsid), RBD (receptor binding domain of the spike protein) and S1 (S1 subunit of the spike protein). For the seasonally occurring human coronaviruses (HCoV: NL63, OC43, 229E, HKU1) nucleocapsid proteins (NP) are used.
For the avidity determination of the IgG antibodies, the avidity reagent can be requested separately.
This test must not be used for clinical diagnosis!
3 Test principle
Highly purified recombinant antigens (NP, RBD and S1 for SARS-CoV- 2, as well as NP for NL63, OC43, 229E, HKU1) are fixed to nitrocellu- lose membrane test strips.
1. The test strips are incubated with the diluted serum or plasma sample with specific antibodies binding to the pathogen antigens on the test strips.
2. Unbound antibodies are then washed away.
3. The strips are incubated in a second step with anti-human immu- noglobulin antibodies (IgG) that are coupled to horseradish peroxi- dase.
4. Unbound conjugate antibodies are then washed away.
5. Specific bound antibody is detected in a colour reaction catalysed by the peroxidase. If an antigen-antibody reaction has taken place, a dark band appears on the strip at the corresponding location.
Control bands are located at the top end of the test strip:
- a) The reaction control below the strip number for which every se- rum/plasma sample must show a reaction.
- b) The conjugate controls (IgG) are used to check the conjugate and strip type used (Ig class specific).
- c) ‘Cut-off control’: The intensity of this band enables an evaluation of the reactivity of the individual antigen bands (see 9.2 Analysis).