Double Helix DNA Model

Making a model is the best way for learning about the elements of a DNA molecule. You can use your model as a separate school project or as an addition to any DNA related science project.A well constructed model enhances your display and results a higher level of attention to your presentation. The model described here is the same model suggested in ScienceProject.com for DNA related science fair projects.

Material: To construct a DNA model you will need the following material: Styrofoam balls (about 100) Double end toothpicks (75) Wooden or metal laboratory stand Brushes for painting the balls Additional material such as paint or water color, glue, string. You may purchase all the required material separately from different local stores or you may prefer to order a kit; however, you should know that kits do not come with paint and glue.

You may already have white glue and water color at home. If not, you may purchase paints and glues from any local hardware store or paint store. 
DNA model kit comes with 100 white balls that you must paint them with any water based or latex paint. (paint is not included)
A kit also contains a base and a column that together form a stand for your DNA model.
A stand makes it easier for your model to be transported from home to school or your science fair. 
Kit also includes brush and matching toothpicks for the balls.
Instructions:
This is a short instruction. If you purchase a kit, please use the URL or web address provided in the kit to access a more comprehensive instruction and tutorial for making your DNA model.

Decide what colors you want to use for small molecules forming each large DNA molecule. The model shown above is based on colors suggested in the kit instructions; however, you may select any other colors for the balls.  Paint all the balls and let them dry. Depending on the paint it may take up to 24 hours for paints to dry. Assemble your stand if it is not already done. A wooden stand is proffered for your model because of lighter weight.

Start from the base and connect the molecules to each other using toothpicks. The large DNA molecule must wrap around the stand's column. 
For the first row make a pair of C-G (Cytosine-Guanine). Add the phosphates to the backbone and then assemble the second row that again can be C-G or A-T (Adenine-Thymine). 
Continue the ladder until you run out of balls.
Note that in constructing the DNA model, we used one ball for each small molecule forming the DNA polymer.
You may use the same balls as atoms to make models of models of different chemicals.

Image in the left shows a molecule of Acetone. White balls are Hydrogen. Black balls are carbon, Red ball is Oxygen (connected with two bonds)Image on the right is a molecule of Benzene.

You can order a materials kit for DNA Model. In addition to the kit you will need some water color or water based paints to paint the balls.