Materials for making DNA models range from household items, such as pipe cleaners, foam balls and toothpicks, to edible candy, such as licorice, marshmallows and gummy bears. Recycled materials, such as aluminium and plastic soft drink bottles, caps and drinking straws, can also be used to make DNA models.
To make a DNA model out of pipe cleaners, cut six different-colored pipe cleaners into one-inch-long pieces. Reserve two colors to represent the pentose sugar and phosphate molecule while the rest represent the four nitrogenous bases: adenine, cytosine, guanine and thymine. Use the pipe cleaner pieces that represent the pentose sugar and the phosphate molecule to make two long strings. Form each string by alternating and joining the two colors. Make pairs with the remaining pipe cleaner pieces such that the color which represents adenine pairs with that of thymine and the same for cytosine and guanine. Connect the pairs to the to a pentose sugar on each string and gently twist the model to form a double helix shape.
A candy DNA model involves using red and black licorice sticks to represent the pentose sugar and phosphate molecule, and different-colored marshmallows or gummy bears to represent the nitrogenous bases. Cut the licorice sticks into one-inch pieces then alternate black and red pieces, while stringing them together using a needle and thread, to form two stands of equal length. Pair the gummy bear nitrogenous bases together and connect them to black licorice segments on each side. Gently twist the strands to form a double helix.