Sunscreen Applicator

In one of our workshops we focus on exploring the effect of UV light on the DNA of the bacterium Escherichia coli and test the effectiveness of sunscreen (https://www.uni.lu/life-en/scienteens-lab/workshops/biology/)

We designed these little adapters to allow us to apply sunscreen or any lotion more evenly across a culture dish.

We use the NUNC EasYDish 35x10 from Thermo Scientific (150460)

The procedure is quite simple:
- Turn the culture dish upside down and place the adapter over it. Make sure that the teeth of the dish holder line up with the opening in the lip of the bottom of the dish (see figure a).
Apply 1 mL sunscreen/lotion to the culture dish and use the scrapper to evenly distribute the sunscreen/lotion.
- Place the scrapper at one end of the adapter and while maintaining contact with the adapter, move of the scrapper to the other end of the dish holder (see figure b).  Make sure that the sunscreen is evenly distributed across the EasyDish (see figure c). If this is not the case, use the scrapper again or add more sunscreen. If done, remove the dish holder (figure d)

The EasYDishes can be flipped over again, placed neatly in the tray and the solution containing the bacteria.

The whole tray can then be placed on a UV transilluminator. The first spot of the tray is closed and can serve as a control i.e. no exposure to UV.
A variety of lotion can be tested e.g. different sunscreens, body lotion, home-made sunscreen, after sun lotions, for their respective effectiveness.