Anti-SARS-CoV-2 IgG ELISA: Replacing the Absorbance Plate Reader by a Regular Scanner with Open-Source Software

The COVID-19 global pandemic is still affecting the world, even considering vaccine applications in most countries, especially due to new variant outbreaks and possibility that they may present immunological escape. Therefore, mass testing relevant infection monitoring restriction policy evaluations, making low-cost easy-to-use tests essential. Serological might also be useful immune response after vaccination. work proposes a less-expensive ELISA test route, using scanner instead of spectrophotometer saturation image as surrogate for absorbance each sample. Images from multiple experiments were selected correlated with their spectrophotometric absorbance. plate images digitized by simple table and, then, preprocessed Hue, Saturation, Value (HSV) transformation, aiming determine which correlates best obtained Saturation better absorbance, presented R2 consistently above 90% between square saturation. methodology showed similar accuracy, sensitivity, specificity original method, all metrics ranging 100% cases. An open-source software was designed analyze images, perform diagnosis, generate reports.