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Author(s): Gregory L. Vogt, EdD, and Nancy P. Moreno, PhD.

Modeling an HIV Particle

This activity helps students visualize the Human Immunodeficiency Virus (HIV) by having them construct 3D HIV particle models from paper. The model to be used represents a complete viral particle. It is a 20-sided polyhedron, called an icosahedron, which approximates the shape of the virus. The completed, three-piece model is about 500,000 times larger than an actual HIV virus particle. Students will combine their finished models into one mass in a first step toward estimating how many HIV particles could be contained inside a white blood cell before being released into the blood stream to attack new cells.

Note: Viral particles, also known as virions, consist of the genetic material (DNA or RNA, shown in red in the image on the slide), a protein coat called the capsid (yellow), which surrounds and protects the genetic material, and sometimes an envelope of lipids (blue) that surrounds the protein coat.


Ask students, Have you ever seen a virus? [It is not possible to observe viruses directly, because they are extremely small.] Encourage students to share what they already know about viruses. List their ideas on the board. Make sure that the facts on the slide are included.

  • Viruses are small infectious agents that require living cells to make copies of themselves (replicate).
  • Viruses replicate by invading living cells.
  • Most viruses are too small to see with a microscope.
  • Viruses are responsible for many different diseases, including the common cold, flu, small pox, and HIV/AIDS.
  • All viruses consist of genetic material (DNA or RNA) surrounded by a protective coat.

Discuss the purpose of the activity with your students. They will learn about the Human Immunodeficiency Virus (HIV) by constructing a paper model that enables them to visualize a single HIV particle. The model will show both the exterior and interior of the particle and serve as a starting point to learn about the virus’s function. 

Funded by the following grant(s)

Science Education Partnership Award, NIH

Grant Number: 5R25RR018605