SARS-Cov-2 IgG ELISA CE

Analysis Performance Evaluation Report

1. Introduction
Report showed the data of performance analysis of SARS-CoV-2 IgG Antibody Diagnostic Kit (ELISA) (hereinafter referred to as the kit), test the different endpoints of the kit to see whether it is according to the design requirements.

2. Performance study
2.1 Percent agreement of negative reference
Fifteen serum samples were collected in hospitals as negative references. The kits were used to test the negative references. The percent agreement of negative reference was 100%.

2.2 Percent agreement of positive reference Fifteen serum samples were collected in hospital as positive references.
The kits were used to test the positive references. The percent agreement of positive reference was 100%.

2.3 Detection limit
One positive serum sample was collected. It was diluted into 1:90, 1:100, 1:110, and 1:120.
The kit was used to test the samples. Every sample was tested for 20 times. The results showed that when the dilution ratio was ≥1:110, the positive rate was ≥95%. The detection limit was determined to be 1:110.

2.4 Precision
The kits was used to test three different concentrations of serum samples. Every sample was tested 20 times on 5 consecutive days. All the CV of between-day was ≤15%.

2.5 Interference
One critical positive and one critical negative sample (basic samples) were collected in hospitals. The positive and negative samples were divided into several parts equally. The samples were added with different interfere substances separately as below. The concentration of Hemoglobin, Bilirubin, Triglyceride and RF did not interfere with the test results of the kits.

Table: concentration of the interfere substances

2.6 Sensitivity and specificity
Clinical validation study of the kit was conducted in 2020 in Guangdong Provincial for Disease Control and Prevention. 222 specimens from clinical samples of patients with suspected SARS-CoV-2 virus infection were tested. Compared with control reagent, the kit demonstrated the sensitivity of 94.03% (63/67) and the specificity of 96.13% (149/155).