Detection of SARS-COV-2 Proteins Using an ELISA Test

Abstract

The coronavirus disease 2019 (COVID-19) global pandemic created an unprecedented public health emergency. Early recognition of an infected person and disruption of the transmission pathway are the keys to controlling this major public health threat around the world. The scientifically reliable screening method is an RT-PCR test that is performed on an ororhinopharyngeal swab in the laboratory. In the current severe SARS-CoV-2 pandemic, it is necessary to identify devices for rapid diagnosis to reduce the spread of the disease. The aim of this study was to provide a qualitative, rapid, sensitive, and specific method for a diagnosis of SARS-CoV-2 infection based on the recognition of specific antigens of the SARS-CoV-2 virus. The device was built by assembling commercially available and custom-made semi-finished products. The method was performed in environments outside the laboratory, i.e., "patient side," with an immediate chemocolorimetric response or with a digital reader using an ELISA method.

Keywords: COVID-19; ELISA; SARS-CoV-2; cytosalivary sampling.

Figure 1

Stages of the preparation of a PVDF strip.

Figure 2

The ELISA assay. The support with the strips was immersed in a solution containing a cell lysate (range: 15 µg/µL–50 ng/µL). A very intense pink/purple colorimetric effect was obtained.

Figure 3

ELISA assays. The support with the strips was immersed in a solution containing a cell lysate (range: 500 pg/µL down to 5 pg/µL). These tests that were carried out with lower protein concentrations still showed a positive result, although with a pale pink color.