Creating DNA models is a great way to learn about how this incredible chemical structure makes up our genes. Using commonly found materials, you can create your own DNA model by combining science and crafts into an interesting project.
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Method 1 of 3: Creating a DNA Model Using Beads and Pipe Cleaners
Step 1. Prepare the necessary materials
You will need at least four strands of pipe cleaner (a strand of wire that is filled with tufted fibers and usually used for cleaning pipes) measuring 12”, and assorted beads of at least six colors.
- Plastic beads are best for this project, although you can use any type of bead that has a hole wide enough for the pipe cleaner to pass through.
- Each of the two pairs of pipe cleaners should be a different color, giving you a total of four pipe cleaners that are preferably black and orange, symbolizing phosphate and deoxyribose, respectively.
Step 2. Cut the pipe cleaner
Take two pipe cleaners of the same color, and cut them into small 2 pieces. You will use these to attach the C--G and T--A beads. Leave the other two pipe cleaners intact.
Step 3. Thread the beads on the pipe cleaner to form a double helix
Use two different colors of beads to represent the sugar and phosphate groups, pairing them with alternating colors along each pipe cleaner.
- Make sure that the two strands that make up the double helix are perfectly aligned, so that the beads are in the same order.
- Leave about half an inch between the beads to allow room to attach another piece of pipe cleaner.
Step 4. Attach your nitrogen base beads
Take four other colors of beads, and match them to each other. Two different colors must always pair up consistently, to represent the pairing of cytosine and guanine, as well as thymine and adenine.
- Place one bead on each end of the 2" pipe cleaner piece, leaving a small space at the end to form a double helix strand.
- It doesn't matter what order the beads are placed in, what matters is that they are paired correctly.
Step 5. Install the beaded pipe cleaner
Take a beaded 2” pipe cleaner and tie the ends along the strand of the double helix.
- Space each of the small pipe cleaner pieces so they always stick over the beads on the same colored side. You need to tie it after every two beads along the strands of the double helix.
- The order of these small pieces doesn't matter, it's up to you how they are arranged along the strands of the double helix.
Step 6. Twist into a double helix
Once all the small pieces of the bead are in place, twist the ends of the double helix in a counterclockwise direction to give the appearance of a true DNA strand. Admire the DNA model you just created!
Method 2 of 3: Creating a DNA Model Using Styrofoam Foam Balls
Step 1. Prepare the materials you will need
For this version of the project, you will need small balls of Styrofoam foam, a needle and string, paint, and a toothpick.
Step 2. Color your Styrofoam ball
Choose six different colors to represent the sugar and phosphate groups, as well as the four nitrogenous bases. Choose the color you like.
- You need to color 16 balls for sugar, 14 balls for phosphate, and 4 different colors for each nitrogenous base (cytosine, guanine, thymine, and adenine).
- You can also choose white, so you don't have to color multiple Styrofoam balls. You can use this white color for sugar balls, as it will greatly reduce the amount of work you do.
Step 3. Pair the nitrogen base
Once the paint is dry, assign one color to each of the nitrogen bases, and then match them accordingly. Cytosine always pairs with guanine, and thymine always pairs with adenine.
- The order of the colors doesn't matter, the important thing is that they're paired correctly.
- Glue a toothpick between each pair, leaving a little extra space at the sharp end of the toothpick.
Step 4. Create a double helix
Using a needle and thread, make a cut long enough to fit 15 Styrofoam balls. Tie a knot at one end of the string, attaching the other side to the needle.
- Arrange fifteen Styrofoam balls of sugar and phosphate alternately. Sugar balls should be more than phosphate balls.
- Make sure that the two strands of sugar and phosphate are in the same order, so that they match up when paired with each other.
- Alternately thread a stringed needle through the center of each Styrofoam ball of sugar and phosphate. Tie the lower end of the rope, to prevent the ball from slipping.
Step 5. Attach the nitrogenous bases to the strands of the double helix
Take a toothpick with the nitrogen base balls attached, and stick the sharp end of the toothpick into the sugar balls on each long strand.
- Plug the nitrogen base pairs only in the Styrofoam ball that represents the sugar, because this is how DNA is actually made up.
- Make sure the toothpick is inserted deep enough so that the base pairs don't fall off easily.
Step 6. Create a double helix
Once all of the base pair stitches have stuck to the sugar, twist the two strands in a counterclockwise direction to create the correct double helix look. Your model is finished!
Method 3 of 3: Creating a DNA Model Using Candy
Step 1. Choose the appropriate candy
To make parts of the chemical structure of sugars and phosphates, use black and red licorice strands with hollow centers. For a nitrogenous base, use candies of four different colors.
- Whatever candy you use, make sure it's soft enough for a toothpick to penetrate.
- If you have one, colored marshmallows make a good substitute for candy.
Step 2. Prepare the other ingredients
Prepare string and toothpicks to use in making the DNA model. The rope will need to be cut to about a foot long, but you can also make it longer or shorter based on the size of the DNA model you want.
- Use two strands of string of the same length to make a double helix shape.
- Make sure you have at least a dozen toothpicks. Depending on how large the model you want to make, you may need more or less than a dozen.
Step 3. Cut the liquorice
Licorice will be hung on strings in alternating colors, and will need to be cut to an inch long.
Step 4. Make candy pairs
In a DNA strand, cytosine (C) pairs with guanine (G), while thymine (T) with adenine (A). Choose four different candy colors to represent these four nitrogenous bases.
- It doesn't matter if the pair is C--G or G--C, as long as they are always paired.
- You can't just make color combinations between pairs. For example, you cannot combine T--G or A--C.
- There are no rules about what color you should choose. Depends on personal preference.
Step 5. Thread the string into the liquorice that you have prepared
Take two strands of string and tie a knot at the bottom of each thread to prevent the liquorice from slipping. Then, thread the string through the hollow center of the liquorice in alternating colors.
- The two colors of liquorice symbolize the sugars and phosphates that form a double helix.
- Choose one color as the sugar group; The nitrogen base candy that you prepared will be attached to this liquorice color.
- Make sure the two licorice strands are in the same color order, so they look good when they are juxtaposed with each other.
- Tie the other end of the string when you're done adding all the liquorice pieces.
Step 6. Attach the candy using a toothpick
Once you've finished pairing the candies based on the C--G and T--A nitrogen base pairs, take a toothpick and stick each piece of candy into both ends of the toothpick.
- Place the candy far enough from each other on each toothpick, so that at least inch of both sharp ends are still sticking out.
- You may make one base pair more than the other; the actual number of base pairs in DNA determines the differences and changes in the genes that are formed.
Step 7. Attach the candy to the liquorice
Spread out the two liquorice strands on a flat surface, then attach a toothpick with the candy attached to the liquorice by inserting the sharp end into the liquorice.
- You should only attach a toothpick to a "sugar" molecule whose liquorice color you have set. So that all toothpicks will be attached to the same liquorice color (for example, on all red liquorice).
- Use all the toothpicks you have the candy on, no leftovers needed.
Step 8. Twist to form a double helix
Once you've placed all the toothpicks on the liquorice, twist the two licorice strands in a counterclockwise direction to give a true double helix spiral appearance. Admire the DNA model you just created!
