Helping my daughter build a DNA model for school out of wire and beads, I realized that this was an ideal object for a set of standardized interlocking parts. This construction set strives for biological accuracy and educational value.

• approximately 65,000,000 : 1 scale
• 10.5 base pairs per twist
• reversible bonds along the spine
• interlocking hydrogen bonds
• major and minor grooves
• representations of carbon and phosphate rings

Each base pair consists of 2 backbone pieces and 2 matching bases. For the pictured model I printed 8 of each base and 32 backbone segments. Ideally you'd print each base in a different color. I printed them all with white ABS and tinted them with Rit dye (about 30 minutes in a solution of 3 parts hot water, 1 part acetone).

The model is under stress when built, so the backbone pieces should be glued to each base. To stabilize the hydrogen bonds I wrapped them with cellophane tape. The tower needs to be stabilized, for which I cut short lengths of acrylic doweling.