A series of incredible photos have emerged online revealing how effective hand washing is as a frontline virus defence.
The six images, recently shared to Instagram by US actor Kristen Bell, show the difference between hands which haven't been washed versus those washed for a full 30 seconds.
The actress explained in a caption that her mother had sent her the snaps which were taken under ultraviolet light as a way of highlighting the importance of handwashing.
Business Insider reports Bell's mother was able to create the images using a UV light and a cream called Glo Germ.
The gel product is rubbed onto the hands like a lotion before being exposed to UV light where it can show a simulated spread of germs.
The Instagram post shared on Bell's page has gathered 426,000 likes and nearly 5000 comments, including many from parents who planned to show the photos to their kids.
One wrote: "I can only imagine what my five-year-old's hands look like under that thing."
And another: "Totally showing this to my kids, fingers crossed it helps."
A third said: "Thank you. So nice to have this photo to show my five-year-old so he could really get a visual. He was thrilled to sing his ABCs while he washed."
According to the Centre for Disease Control and Prevention you should wash your hands for at least 20 seconds — or as long as it takes for you to sing 'Happy Birthday' twice.
When it comes to the issue of hand washing versus hand sanitiser, an Australian infectious diseases expert weighed in earlier this week telling news.com.au both were important.
According to Professor Peter Collignon of the Australian National University Medical School, hand washing is the more effective method for keeping hands germ-free.
He advised people using hand sanitisers, a product which is ideal for on-the-go situations, to make sure anything they purchased had the correct concentration of alcohol.
Sanitisers generally have an alcohol concentration of between 60 and 95 per cent.
"It's not the end of the world if you miss out on buying alcohol hand rub because washing your hands with soap and water is also very effective, there is not a huge amount of difference," Prof Collignon said.
"One is just more convenient than the other and contains alcohol.
"You can put it in your pocket and don't have to be near a sink or basin to use it."