Making a DNA model is a useful way to learn about this magnificent structure that underlies genetics. Using common materials you can build models for science research or more ambitious projects.
Steps
Method 1 of 3: Make a Model with Beads and Pipe Cleaner
Step 1. Put everything you need together
You will need at least four 25cm pipe cleaners and assorted beads in at least six colors.
- Plastic pony beads are best, although any type will still be fine as long as it has a hole large enough for the pipe cleaner to pass through.
- Each pair of cleaners must be different for a total of four in two different colors.
Step 2. Cut the pipe cleaners
Take two of the same color and cut them into 5 cm strips. You will use them for the C-G and T-A pairs of beads. Leave the others at their normal length.
Step 3. Thread the beads to build the double helix
Use two different colors for sugars and phosphates and alternate them along each pipe cleaner.
- Make sure the two strands forming the double helix match and the beads must be in the same order.
- Leave some space between each bead to allow you to connect the other pieces of pipe cleaner.
Step 4. Create the nitrogen bases with the beads
Take the other four bead colors and assemble them. Always use the same color pairs to represent cytosine and guanine, thiamine and adenine.
- Place one bead from each pair at the end of the 5cm section of pipe cleaner. Leave some room for screwing in the double helix filaments.
- No matter the order in which you place the beads on the pipe cleaner, the important thing is that the pairs are correct.
Step 5. Connect the cleaners to each other
Take the 5 cm sections with the beads and wrap them around the strands of the double helix.
- Space each piece so that it is always attached on top of and next to a bead of the same color. For a correct assembly, add a piece for every two beads.
- The order of the small pieces doesn't matter, it's up to you and how you want to arrange the double helix strands.
Step 6. Screw in the double helix
Once all the bead sections are joined, screw the ends of the double helix counterclockwise to give it the look of a real strand of DNA. Your model is finished!
Method 2 of 3: Make a Model with Styrofoam Balls
Step 1. Put the material together
For this version you will need Styrofoam balls, a needle, thread, paint and toothpick.
Step 2. Paint the Styrofoam
Choose six different colors to represent the sugar and phosphate groups, and the four nitrogen bases. It can be six colors to choose from.
- You will need to paint 16 sugars, 14 phosphates and 4 different colors for each nitrogen base (cytosine, guanine, thiamine and adenine).
- You can choose to leave a white ball so you don't have to color everything, perhaps to represent the simplest sugar. You will reduce the work a lot.
Step 3. Pair the nitrogen bases
Once the color is dry, assign one to the nitrogen bases and pair them with the corresponding base. Cytosine always goes with guanine and thiamine always goes with adenine.
- The order of the colors does not matter as long as the pairs are correct.
- Insert a toothpick between each pair, leaving some extra space at the tip.
Step 4. Create the double helix
Using a needle and a piece of thread long enough for 15 Styrofoam balls. Tie a knot at the end of the thread and pass the other end through the eye.
- Line up the styrofoam sugar with the phosphate so that they alternate in groups of 15. There should be more sugar than phosphates.
- Make sure the two strands of sugar and phosphate are in the same order, so they line up when you arrange them next to each other.
- Sew through the center of each ball, alternating them. Tie the yarn at the end of each ball to keep it from moving.
Step 5. Attach the nitrogen bases to the double helix filaments
Take the toothpicks with the nitrogen bases and thread the pointed parts to the corresponding sugars on each strand.
- It only attacks pairs that represent sugars because that's how it is in real DNA.
- Make sure you secure the toothpicks securely to the base pairs so they don't jump off.
Step 6. Turn the double helix
Once all the toothpick bases are attached to the sugars, turn the double helix counterclockwise to simulate the look of a real helix. Your model is finished!
Method 3 of 3: Making the Model with Candies
Step 1. Choose the treats you will use
To make the sugar and phosphate sides, use black and red licorice threads with a hollow center. For nitrogen bases, use four different colored gummy bears.
- Whichever candy you choose, make sure it's soft enough to stick with a toothpick.
- Gummy bears can be replaced by colorful marshmellows.
Step 2. Prepare the other materials
Put threads and toothpicks together. The strands should be about 30 cm long, although you can make them shorter or longer depending on the size you want.
- Use two threads of equal color and length to make the double helix.
- Make sure you have at least a dozen toothpicks. The number of toothpicks you will use may vary based on the size of the model.
Step 3. Cut the licorice
The filaments will be wrapped in alternating colors and therefore must be 3 cm long each.
Step 4. Pair the gummy bears
In DNA strands, pairs of cytosine and guanine (C and G) are tied together, just like thiamine and adenine (T and A). Choose four different colored bears that will represent the nitrogen bases.
- It doesn't matter if the pair is C-G or G-C, as long as it's the same.
- You cannot mix colors between pairs. So no T-G or A-C.
- The colors you choose are arbitrary; based only on your preferences.
Step 5. Wrap the licorice
Take two strands of licorice and tie a knot at the bottom to keep it from slipping. Then he binds the filament using the cavity in the center, in alternating colors.
- The two colors symbolize the sugars and phosphate that create the filaments of the double helix.
- Choose a color for the sugar group - the nitrogenous bases of gummy bears will stick to this color.
- Check that your two strands have licorice in the same order so they line up when they are next to each other.
- Tie a second knot at the other end of the strand once you are done adding the licorice pieces.
Step 6. Attach the bears with toothpicks
Once all the bears are paired following the pattern C-G and T-A, use the toothpicks to keep them together.
- Push the bears far enough into each toothpick so that at least 0.5cm of the tip sticks out.
- You can have more pairs of one type than another - the pairs in real DNA determine the genetic differences.
Step 7. Attach the licorice bears
Place the two licorice strands on your work surface and connect them to the bears by inserting the tips of the toothpicks into the licorice.
- You should only attach toothpicks to certain "sugar" molecules. These will be represented by pieces of licorice of the same color (for example all red ones).
- Use all the teddy bears stuck by toothpicks and don't worry about keeping any.
Step 8. Spin the double helix
Once you have joined the licorice bears, turn the filaments counterclockwise to give the idea of the spiral. Here is your complete DNA model!
