# An Efficient UV-C Disinfection Approach and Biological Assessment Strategy for Microphones  
[PERSON]  
1W. J. Kolff Institute-FB41, Department of Biomedical Engineering-FB40, University Medical Center Groningen, University of Groningen, 9713 AV Groningen, The Netherlands, [EMAIL_ADDRESS]  
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2 LAC Labs GmbH, Krummenau 4, 53577 Neustadt, Germany; [EMAIL_ADDRESS]  
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3 Department of Medical Microbiology and Infection Prevention, University Medical Center Groningen, University of Groningen, 9713 AV Groningen, The Netherlands, [EMAIL_ADDRESS] (J.J.A.V.-L.); [EMAIL_ADDRESS] (A.L.W.H.); [EMAIL_ADDRESS] (J.M.v.D.)  
[PERSON]. [PERSON]  
3 Department of Medical Microbiology and Infection Prevention, University Medical Center Groningen, University of Groningen, 9713 AV Groningen, The Netherlands, [EMAIL_ADDRESS] (J.J.A.V.-L.); [EMAIL_ADDRESS] (A.L.W.H.); [EMAIL_ADDRESS] (J.M.v.D.)  
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3 Correspondence: [EMAIL_ADDRESS]  
[PERSON]  
1W. J. Kolff Institute-FB41, Department of Biomedical Engineering-FB40, University Medical Center Groningen, University of Groningen, 9713 AV Groningen, The Netherlands, [EMAIL_ADDRESS]  
Footnote 1: [[https://www.mdpi.com/journal/applsci](https://www.mdpi.com/journal/applsci)]([https://www.mdpi.com/journal/applsci](https://www.mdpi.com/journal/applsci))  
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by various individuals reduces the risk of infections. Disinfection of such objects could prevent the microbes from spreading and thereby prevent unnecessary suffering. One such item is a microphone.  
A microphone is typically a device that is shared by various individuals, and because the microphone is in close contact with the oral cavity and aerosols, the chance for microbes to transfer from the oral cavity to the surface of the microphone is high (Figure 1). Hence, the industry that uses microphones would benefit substantially from a procedure that enables disinfection of microphones and thereby lowers the chances of possible spread and transmission of microbes, including SARS-CoV-2.  
Here our aim was to setup an infection methodology and test a new device that would allow disinfection of microphones by using UV-C irradiation. UV-C is known to damage viruses and bacteria, rendering them non-infectious by directly damaging their genetic material (DNA/RNA) and proteins [11]. Other approaches for disinfection are known, involving the application of alcohol, hydrogen peroxide, or autoclaving, but these methods could damage the microphones. Disinfection with UV-C is an effective approach and, when applied in a short enough time-span, it will not harm the material in question. It is therefore regarded as a useful disinfection tool in hospitals and more general settings to prevent the transmission of SARS-CoV-2 [12; 13]. The use of UV-C has already been applied to inactivate various microorganisms [14; 15], especially bacteria [16; 17] and viruses [11; 18; 19], including SARS-CoV-2 [20; 21; 22], in different conditions, such as aerosols [19], surfaces [23; 24], medical materials [25], dairy products [26], and other foods [27]. Accordingly, we developed a novel UV-C irradiation device for the disinfection of microphones. To test the efficacy of our device, microphones were inoculated/contaminated with a model virus, the M13 bacteriophage. The M13 bacteriophage was used as a representative model to be able to test the device and our experimental protocol in a biologically safe manner, as this virus is non-infective towards humans [28; 29]. To illustrate the general applicability of the device, UV-C treatment of M13 in suspension was compared to UV-C treatment of influenza virus in suspension, which was previously shown to respond to UV-C in a similar manner as SARS-CoV-2 on contaminated solid surfaces [30].