BUSCADOR RECOLECTA

The optical absorption coefficient of culture media is critical for the survival analysis of pathogens under optical irradiation. The quality of the results obtained from experiments relies on the optical analysis of the spatial distribution of fluence which also depends on the geometry of the sample. In this contribution, we consider both the geometrical shape and the culture medium's absorption coefficient to evaluate how the spatial distribution of optical radiation affects pathogens/viruses. In this work, we exposed SARS-CoV-2 to UV-C radiation ([Formula: see text] = 254 nm) and we calculated-considering the influence of the optical absorption of the culture medium-a characteristic inactivation fluence of [Formula: see text] = 4.7 J/m2, or an equivalent 10% survival (D90 dose) of 10.8 J/m2. Experimentally, we diluted the virus into sessile drops of Dulbecco's Modified Eagle Medium to evaluate pathogen activity after controlled doses of UV irradiation. To validate the optical absorption mode, we carried out an additional experiment where we varied droplet size. Our model-including optical absorption and geometrical considerations-provides robust results among a variety of experimental situations, and represents our experimental conditions more accurately. These results will help to evaluate the capability of UV disinfecting strategies applied to a variety of everyday situations, including the case of micro-droplets generated by respiratory functions., This work has been partially supported by funding contracts with Luminalia Ingeniería S.L., and TK Elevator Manufacturing Spain, and by a grant from the Comunidad de Madrid with reference COV20-01244-CM. This publication was also supported by the European Virus Archive GLOBAL (EVA-GLOBAL) project that has received funding from the European Union's Horizon 2020 research and innovation program under grant agreement 871029. The authors are especially grateful to Luis Prada and Luis Estrada for their contribution to clarify some important issues of the UV sources, to Dr. Alexander Cuadrado for his encouragement in pursuing these results, and to Dr. Irene Alda for her careful reading and language review of this manuscript., Peer reviewed

RNA sequence of SARS-CoV-2 used for the computational analysis of the UV-inactivation process.