Fig. 3

Schematic sketch of COVID-19 diagnostic process. Respiratory specimens collected and kept in appropriate transport. During samples extraction cells are lysed and RNA is extracted, amplified and detected by either PCR or isothermal route. Detection is by either use of specific fluorescent dyes or a calorimeter. For CRISPR-based technology, the activated Cas12 cleaves reporter labels resulting in generation of a fluorescent signal which is detected and quantified. In the sequencing process, the cDNA is converted into a form compatible followed by detection of these cDNA sequences digitally. The antigen tests scans for the presence of SARS-CoV-2 antigens whereas the antibody tests scans for the presence of antibodies produced against the virus [49]