DNA Model on Base

Quick Answer: A DNA model on base is an assembled double-helix model of deoxyribonucleic acid mounted upright on a base. It stays built, so teachers can use it at the front of the class to show the two sugar-phosphate backbones, the paired bases between them and the twist of the helix.

Reading the Double Helix on a Display Model

On a DNA model on base, the two outer spirals represent the sugar-phosphate backbones and the rungs between them are base pairs. Each rung joins a purine (adenine or guanine) to a pyrimidine (thymine or cytosine), which keeps the width of the helix constant along its length. Colour coding normally identifies the four bases and the backbone parts, and a key written up beside the model helps students read it.

Fixed upright, the model also holds the geometry that loose kits struggle to keep: the helix is right-handed, and the backbones are not evenly spaced, leaving a wider major groove and a narrower minor groove that wind around the molecule. Proteins that read DNA, such as transcription factors, bind mostly in the major groove, a point older students can see on the model.

The structure has a history teachers like to tell. In 1953 James Watson and Francis Crick published the double helix, drawing on X-ray diffraction work from Rosalind Franklin and Maurice Wilkins, including the image known as Photo 51. Classroom display models follow the same idea as the wire-and-plate model Watson and Crick assembled in Cambridge.

Specifications

Applications

• Introducing the structure of DNA before students build their own strands
• Pointing out the major and minor grooves when teaching how proteins recognise DNA sequences
• History of science lessons on Watson, Crick, Franklin and Wilkins
• A permanent reference piece on the biology laboratory shelf during genetics revision

Care & Handling

• Lift the DNA model on base by the base, never by the helix, which can bend or loosen at its joints.
• Dust regularly with a soft brush; a puff of compressed air clears the gaps between base pairs.
• Keep it away from radiators and sunny windowsills, where plastic parts can warp or fade.

Why Choose LabEquip

Schools and colleges typically buy one DNA model on base for each biology room, as a reference piece that stays built all year. It pairs naturally with the hands-on DNA activity model, and both belong to LabEquip’s biology lab products. Use the contact page to ask about size and colour coding.

Frequently Asked Questions

Why are the two sides of the helix called backbones?

Each side is a chain of alternating deoxyribose sugars and phosphate groups. These chains carry the bases and give the molecule its structure, much as the spine supports the body.

What are the major and minor grooves?

Because the two backbones are not evenly spaced around the helix, the gaps between them form a wide groove and a narrow groove. Many DNA-binding proteins read the base sequence through the major groove.

Is the helix right-handed or left-handed?

The usual form of DNA, called B-DNA, is a right-handed helix, and classroom models copy this. A left-handed form, Z-DNA, exists for some sequences but is not what standard models show.

Why does a purine always pair with a pyrimidine?

A purine is a larger two-ring base and a pyrimidine a smaller one-ring base. Pairing one of each keeps the distance between the backbones the same all along the molecule.

Who discovered the double helix?

James Watson and Francis Crick proposed the structure in 1953. Their model relied on X-ray diffraction data from Rosalind Franklin and Maurice Wilkins at King’s College London.

Can students take the model apart?

It is intended to stay assembled as a display piece. For building and separating strands, a hands-on activity model or an assembly kit is the better choice.

Last Updated: September 2026