Patient Testing: Patient samples were tested using the SARS-CoV-2 Spike Protein Serological IgG ELISA Kit #20154. Serum or plasma was obtained from donors who had been diagnosed with SARS-CoV-2 (diagnosed positive n=28) or from presumed uninfected donors collected prior to the SARS-CoV-2 outbreak (presumed negative n=62). Samples were heat-inactivated (56°C for 30 min) and diluted 1:800 prior to running the assay, as described in the protocol. Samples were considered positive, negative, or inconclusive based on the criteria described in the “Data Analysis” section of the protocol for the kit. Positive percent agreement (PPA) and negative percent agreement (NPA) were calculated from these data.
Note: We are continuing to test more samples as available. For the most up-to-date set of data, always refer to the product page for #20154 on the website.
Intra-Assay Precision: Three different serum samples were each tested in 16 replicates using a single assay kit of SARS-CoV-2 Spike Protein Serological IgG ELISA #20154. Intra-assay CV (%) was calculated for each sample, and each replicate was correctly identified as being positive or negative when compared to the Negative Control using the cutoff criteria described in the attached protocol.
Inter-Assay Precision: Six different assay kits from one lot of material were tested using 3 different serum samples run in duplicate wells and Positive and Negative Controls run in 4 replicate wells. Inter-assay CV (%) was calculated for each sample, and each assay kit correctly identified the samples as being positive or negative when compared to the Negative Control using the cutoff criteria described in the attached protocol.
Patient Testing: Patient samples were tested using the SARS-CoV-2 Spike Protein Serological IgG ELISA Kit #20154. Serum/plasma samples were heat-inactivated (56°C for 30 min) and diluted 1:800 prior to running the assay, as described in the protocol. Background subtracted absorbance values at 450 nm are plotted for each serum/plasma sample, with values corresponding to samples obtained from donors who had been diagnosed with SARS-CoV-2 (diagnosed positive n=28) on the right, and values corresponding to samples from presumed uninfected donors collected prior to the SARS-CoV-2 outbreak (presumed negative n=62) on the left. Also shown is the cutoff line above which samples are considered positive (blue line), and the negative cutoff line (red line), below which samples are considered negative. Cutoff values were calculated as described in the “Data Analysis” section of the protocol for the kit.
|Product Includes||Volume||Solution Color|
|Spike Protein Coated Microwells II||96 tests|
|Anti-Human IgG, HRP-linked Antibody (ELISA Formulated)||1 ea||Red (Lyophilized)|
|Sample Diluent A 71637||25 ml|
|HRP Diluent||11 ml||Red|
|ELISA Wash Buffer (20X) 9801||25 ml|
|TMB Substrate 7004||11 ml|
|STOP Solution 7002||11 ml|
|Sealing Tape||2 ea|
|ELISA Kit #20154 Positive Control||1 ea|
|ELISA Kit #20154 Negative Control||1 ea|
The SARS-CoV-2 Spike Protein Serological IgG ELISA Kit is a solid phase ELISA that detects binding of human IgG to full-length SARS-CoV-2 spike protein (S-protein). Full-length spike protein has been coated onto microwells. After incubation with sample, human IgG specific for spike protein is captured on the plate. The wells are then washed to remove unbound material. Anti-Human IgG, HRP-linked antibody is then used to recognize the bound IgG. HRP substrate, TMB, is added to develop color. The magnitude of optical density for this developed color is proportional to the quantity of IgG specific for spike protein.
*Antibodies in kit are custom formulations specific to kit.
This ELISA Kit Is Intended For Research Use Only. Not For Use in Diagnostic or Clinical Procedures.
NOTE: Prepare solutions with deionized/purified water or equivalent. Prepare only as much reagent as needed on the day of the experiment.
NOTE: Equilibrate all materials and prepared reagents to room temperature prior to running the assay.
NOTE: Sample storage/handling, including heat-inactivation of samples, can potentially affect observed signals. Therefore, it is strongly recommended that in addition to the Positive and Negative Controls included with the kit, the user includes their own negative and positive patient samples as controls when running the assay in order to establish an appropriate cutoff value.
NOTE: Initial color of positive reaction is blue, which changes to yellow upon addition of STOP Solution.
Protocol Id: 2024
The SARS-CoV-2 Spike Protein Serological IgG ELISA Kit detects endogenous levels of human IgG directed to full-length SARS-CoV-2 spike protein (S-protein).
The cause of the COVID-19 pandemic is a novel and highly pathogenic coronavirus, termed SARS-CoV-2 (severe acute respiratory syndrome coronavirus-2). SARS-CoV-2 is a member of the Coronaviridae family of viruses (1). The genome of SARS-CoV-2 is similar to other coronaviruses, and is comprised of four key structural proteins: S, the spike protein, E, the envelope protein, M, the membrane protein, and N, the nucleocapsid protein (2). Coronavirus spike proteins are class I fusion proteins and harbor an ectodomain, a transmembrane domain, and an intracellular tail (3,4). The highly glycosylated ectodomain projects from the viral envelope surface and facilitates attachment and fusion with the host cell plasma membrane. The ectodomain can be further subdivided into host receptor-binding domain (RBD) (S1) and membrane-fusion (S2) subunits, which are produced upon proteolysis by host proteases at S1/S2 and S2’ sites. S1 and S2 subunits remain associated after cleavage and assemble into crown-like homotrimers (2,4). In humans, both SARS-CoV and SARS-CoV-2 spike proteins utilize the angiotensin-converting enzyme 2 (ACE2) protein as a receptor for cellular entry (5-7). Spike protein subunits represent a key antigenic feature of coronavirus virions, and therefore represent an important target of vaccines, novel therapeutic antibodies, and small-molecule inhibitors (8,9).
Explore pathways + proteins related to this product.
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