There are bulbs installed within a UV toothbrush sanitizer that emit short-wavelength light to eliminate and kill all inactive microorganisms. Bacteria can be defined as a group of single-celled microorganisms that reproduce through cell division. The light destroys the bonds of nucleic acids to sanitize the toothbrush, which makes up the DNA. Nucleic Acids are small biomolecules essential to all forms of life that make up DNA. When the DNA is damaged and disrupted, the bacteria are not able to reproduce and perform the functions they need to remain active. Their growth stops at this point. Ultraviolet rays are invisible, the human eye cannot see them. There are three different bands of Ultraviolet light which depend on the wavelength. It is the shortwave UV-C radiation that is effective at removing germs on your toothbrush. When you place the toothbrush in the sanitizer for a long period, there are better chances of the UV functioning efficiently and killing it than if you put it under it for a short period. For your information, bacteria can also be shielded by other particles as well as being better able to withstand UV, but after some minutes of exposure in most cases, particularly with our subject, the toothbrushes. This way effectiveness of nearly a hundred percent is achieved by the toothbrush sanitizers. However, in some toothbrush sanitizers, water and air are repeatedly circulated to change the conditions and allow for several passes of the Ultraviolet light onto the bacteria to achieve the most effective removal.