Ultraviolet light is often used as one of the methods to slow down the growth of microbes and disinfect some areas. It is explained by the UV radiation’s capability to cause the death of the cell because of the interference into DNA replication (Rezaie et al., 2020). Thus, to prove the UV radiation’s impact on the growth of microbes, a special experiment was conducted.
The study rested on the hypothesis formulated to investigate UV light’s capabilities:
The prolonged exposure to UV radiation damages the DNA of microbial cells, prevents them from growing, and leads to their death, which helps to disinfect surfaces.
The experimental method with control and exposed areas was employed to prove the hypothesis. Three agar plates with S. aureus were exposed to ultraviolet radiation. Half of the plates were covered with a white paper sheet to prevent UV light from penetrating and affecting the control areas. The duration of exposure comprised 15 sec, 1 min, and 5 min. After the procedure, the plates were left for 24 hours at 370 C for incubation.
The results prove UV radiation’s ability to destroy microbial cells. The graph below shows that the exposure time directly impacts the number of exposed colonies.
The first 15-second session demonstrated growth of more than 500 colonies, with no reduction. The second session, 1 min, shows that only 1-20 colonies emerged, or slight growth was observed. Finally, UV radiation exposure of 5 minutes resulted in 0 colonies or zero growth.
Altogether, the results of the experiment prove the hypothesis and the UV light’s ability to destroy microbial cells. The prolonged impact of this agent of around 1 minute and more can suppress the growth of microbes and destroy them. In such a way, UV radiation can be used as a potent disinfection tool.
Reference
Rezaie, A., Leite, G. G. S., Melmed, G. Y., Mathur, R., Villanueva-Millan, M. J., Parodi, G., Sin, J., Germano, J. F., Morales, W., Weitsman, S., Kim, S. Y., Park, J. H., Sakhaie, S., & Pimentel, M. (2020). Ultraviolet A light effectively reduces bacteria and viruses including coronavirus. PloS One, 15(7), e0236199. Web.