Cell-based assay

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.

Cell-based assay

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.

Cell-based assay

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.

Cell-based assay

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.