How to Make a DNA Ladder

Making a DNA model is useful for a student to understand the relationships within the DNA strand.

It is common for science teachers to assign the project of constructing a model of DNA. Making a DNA model is useful for a student to understand the relationships within the DNA strand. Once this relationship is understood, the concept of how DNA replicates when a cell divides is simple to understand as well.

Things You'll Need

• Pipe cleaners
• Beads with holes in four different colors (all the same size)
• Scissors

Instructions

1. Put two of your beads together, touching each other on a table or other flat surface.

2. Lay a pipe cleaner next to the two beads.

3. Cut the pipe cleaner to a length 3/4 inch longer than the length of the two beads, using the two beads as a measuring tool. Cut at least 10 more pipe cleaner pieces to the same length.

4. Decide which color bead will be associated with each of the four bases found in DNA. You may wish to write this information down so you don't become confused during the construction of your ladder.

5. Slide pairs of beads onto each of the short pieces of pipe cleaner to represent the two base pairs. Remember which colors you have assigned to each base and remember the correct pairing: Cytosine-Guanine and Adenine-Thymine.

6. Twist the extra pipe cleaner that sticks out from each of the sides of the bead pairs to two other pipe cleaners, forming a ladder that has the short pipe cleaners with the beads as rungs.

7. Twist the ladder to form the standard DNA shape.

Resources

• Read this Article in Spanish