Easy Science Fair Projects: How to Make a DNA Model at Home
By Keren Perles
If you’re doing a science project on DNA molecules, you might consider adding a three-dimensional DNA model to your display. These 3-D DNA models are relatively easy to make, and one of them is even edible!
Use Candy - And Then Eat Your Project!
Cut red and black licorice into 1-inch long pieces. Use a needle and thread to string the pieces together, alternating red and black. Repeat with another piece of thread. These strings of licorice will represent the pentose sugar molecules and the phosphate molecules that run along the lengths of the DNA molecule. Lay the two strings alongside each other. Then find four different colors of gummy bears for the nucleotide bases, and decide which ones will be adenine, thymine, cytosine, and guanine. Take two of the bases that naturally pair (adenine and thymine, or cytosine and guanine), and place them between two of the sugar molecules on the strings. Press a toothpick through one sugar molecule, the two nucleotides, and the other sugar molecule. Continue to do this for all of the sugar molecules on the strings. Carefully twist the strings to form a double helix. This is one of the more interesting 3D DNA models, because you can eat it when you’re done! (See this article for more edible science projects.)
Easy Twisting Pipe Cleaners
Pipe cleaners are particularly easy to connect, so they make great supplies for a DNA model. Choose six colors of pipe cleaners, and cut them each into 1-inch long pieces. Two of these colors will represent the pentose sugar and phosphate molecules, and the other four will represent the nucleotides. Twist the first two colors together, alternating them, to make two long strings. Then twist several pairs of nucleotides together, making sure to pair them correctly (adenine to thymine, and cytosine to guanine). Connect these pairs to a pentose sugar molecule from each strand. Twist the DNA molecule gently to give it a double helix shape.
Foam Balls and Toothpicks - The Most Realistic
This DNA model is a bit more complicated than the others, and it requires more expensive art supplies. Buy some small foam balls from a craft store and paint them six different colors with non-acrylic paint. Two of the colors will represent the pentose sugar and phosphate molecules, and the other four will represent the nucleotides. Use toothpicks to connect the balls to each other (put a bit of glue on each end of the toothpick to stabilize the model), and follow the directions for the previous two 3D DNA models. Instead of twisting the model at the end, however, you’ll have to start rotating the foam balls very gently as you go along in order to form the double helix.