Validation of new equipment for SARS-CoV-2 diagnosis in Ecuador: Detection of the virus and antibodies generated by disease and vaccines with one POC device
Fig 5
Detection of COVID-19 antibodies in sera samples by ELISA assays in the PLUM device, validation under field conditions.
(A) Distribution of spike-RBD ELISA absorbance (ABS) relative ratio as determined by a microplate reader against PLUM reading units (PRU) relative ratio from 44 positive (red dots) and 18 negative (blue dots) sera samples. (B) Distribution of N ELISA ABS relative ratio against PRU relative ratio from 14 positive and 48 negative sera samples. (C) Distribution of seroprevalence results from the average ABS from spike-RBD and N against the average PRU from the same antigens using nine positive and 18 negative sera samples. Cohen’s kappa statistics are shown. Dashed lines represent the threshold determined by ROC curve analysis (Table 3).