Assign each of the four DNA bases to a specific color. Use small candies of these colors, such as gum drops, to represent each base. For example: blue/adenine, yellow/cytosine, green/thymine, orange/guanine.
Cut licorice sticks into small pieces and string them together. Licorice pieces should be cut into pieces around an inch in length. Thread alternating pieces of red and black licorice onto two separate strings. The resulting strands should be of equal length.
Pair together the correct candies. In DNA the base adenine will only pair with thymine, while cytosine will only pair with guanine. Thread, for this example, each blue candy onto a toothpick with a green candy. Do the same for the yellow and orange candies.
Connect the candy pairs to the red licorice strands. Each red section of the strand will contain one pair of candies, or bases. Stick each end of the toothpick from the candy pairs into the two parallel pieces of licorice in each section. If desired, the candies may be connected to the black licorice sections instead of the red, as long as only one color of licorice connects with the candy bases.
Twist the strands to create the create the shape of DNA, which looks similar to an X.