Related Experiment Video
Updated: Aug 30, 2025

Inactivation of Pathogens via Visible-Light Photolysis of Riboflavin-5′-Phosphate
Published on: April 6, 2022
In Vitro Inactivation of SARS-CoV-2 Using Gamma Radiation
Anders Leung1, Kaylie Tran1, Jonathan Audet1
1National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada.
Introduction:
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is classified as a Risk Group 3 pathogen; propagative work with this live virus should be conducted in biosafety level-3 (BSL-3) laboratories. However, inactivated virus can be safely handled in BSL-2 laboratories. Gamma irradiation is one of the methods used to inactivate a variety of pathogens including viruses.
Objective:
To determine the radiation dose required to inactivate SARS-CoV-2 and its effect, if any, on subsequent polymerase chain reaction (PCR) assay.
Methods:
Aliquots of SARS-CoV-2 virus culture were subjected to increasing doses of gamma radiation to determine the proper dose required to inactivate the virus. Real-time quantitative polymerase chain reaction (RT-qPCR) data from irradiated samples was compared with that of the non-irradiated samples to assess the effect of gamma radiation on PCR assay.
Results:
A radiation dose of 1 Mrad was required to completely inactivate 106.5 TCID50/ml of SARS-CoV-2. The influence of gamma radiation on PCR sensitivity was inversely related and dose-dependent up to 0.5 Mrad with no further reduction thereafter.
Conclusion:
Gamma irradiation can be used as a reliable method to inactivate SARS-CoV-2 with minimal effect on subsequent PCR assay.
Related Concept Videos
Physical Methods for Controlling Microbial Growth: Radiation and Filtration
In-vitro Mutagenesis
Methods of Sterilization I: Physical Methods
Steam sterilization uses non-toxic, low-cost moist heat in the form of saturated steam under pressure, which is fast, microbicidal, and sporicidal, and quickly warms and penetrates fabrics. Autoclaves, or steam sterilizers, expose each item to direct steam contact for a predetermined time at the necessary...
Methods of Sterilization II: Chemical Methods
Using chemical sterilization rather than heat to clean out equipment is recommended. It eradicates and removes all bacteria,...

