DNA can be displayed with something as easy as candy. An edible double helix is a great way to get someone interested in DNA. With a little bit of candy and a little bit of time you can visually explain the inner workings of a DNA molecule. For this DNA model we use licorice, and marshmallows to represent the nucleotide bases and hydrogen bonds, as well as the sugar deoxyribose and the phosphates. For this DNA model we use:
- Red and black licorice
- 4 colors of gumdrops
- White marshmallows
- First, assign names to the gumdrops. For this tutorial we used: green-adenine, blue-thymine, red-cytosine, yellow-guanine. To make this as authentic as possible pair the bases accordingly. Adenine would naturally pair with thymine, or A with T. Cytosine would naturally pair with guanine, or C with G.
- Next, decide the names for the candy pieces. For the purpose of these instructions the black licorice is the sugar deoxyribose, and the red are the phosphate groups. To begin, you will need to cut the licorice sticks into one inch pieces.
- Then, using the toothpicks, pair the gumdrops. To separate each of the gumdrops you need a white marshmallow. Use two gumdrops, then one marshmallow, then two gumdrops. You can make the poles as long as you want them to be, however, this model has one nucleotide base for each black licorice piece.
- Next, place the cut pieces of licorice on the wire in an alternating fashion ending both ends with red. Make 2 equally long poles. Secure both ends to keep the pieces from moving, leaving long tails. Then, fasten the tails together for an easy place to hold the DNA model.
- Place the ‘ladder’ flat and pierce the toothpicks through the black licorice or the sugar deoxyribose. You should attach the toothpicks in alternating color pairs.
- Turn the ladder so it twists and you now have your very own candy double helix DNA strand. The thicker the wire used the easier it would be to have the DNA model stay how you twist it.
This particular DNA model is not especially stable. It would be more for engaging interest in the topic. You can substitute the candy for beads to make a more stable and non-perishable version of the same model. The instructions would be the same, except the amounts. Depending on the size of beads you would use, the DNA model could be the size of earrings, or the size of a soda bottle.