From the 2010 Holiday Lectures — Viral Outbreak: The Science of Emerging Disease

Dengue Fever Re-Emergence in the Americas

Since the 1960s dengue fever has spread to many countries and total case numbers have exploded.

24 seconds

Viral Geometry and Structural Diversity

The geometric structures of viruses are beautiful and can be used, along with genomic information, to identify them.

3 minutes 22 seconds

Structure of Dengue Virus

The dengue virus's outer envelope proteins form symmetrical units and overlay the lipid envelope, capsid, and the RNA genome.

58 seconds

The Chemical Structure of DNA

DNA's chemical properties can be harnessed for a variety of biotechnology applications.

2 minutes 45 seconds

The Polymerase Chain Reaction (PCR)

PCR is a standard laboratory technique that allows amplification of specific segments of DNA based on complementarity.

55 seconds

Running a Virochip Experiment

A sample is put on a Virochip microarray, and results are compared to databases of all known viral sequences.

2 minutes 9 seconds

Dengue Virus Enters a Cell

Infection begins when the dengue virus uses receptors on an immune cell's surface to gain entry and release its genome.

1 minute 24 seconds

Dengue Virus Life Cycle

Dengue virus has sophisticated mechanisms for entering a cell, for replicating its RNA genome, and for transcribing proteins.

4 minutes 12 seconds

Life cycle of malaria

Part 1: Human host

When a malaria-carrying mosquito bites a human host, the malaria parasite enters the bloodstream, multiplies in the liver cells, and is then released back into the bloodstream, where it infects and destroys red blood cells.

4 minutes 17 seconds

Part 2: Mosquito host

A mosquito becomes infected with malaria when it sucks the blood from an infected human. Once inside the mosquito, the parasites reproduce in the gut and accumulate in the salivary glands, ready to infect another human host with the next bite.

3 minutes 59 seconds

From the 2007 Holiday Lectures — AIDS: Evolution of an Epidemic

Antigen presentation and CTL

How a cell infected by a virus signals cytotoxic T lymphocytes to kill the cell before the virus replicates and spreads.

2 minutes 34 seconds

AZT blocks reverse transcriptase

HIV's reverse transcriptase mistakes AZT for thymidine. Once incorporated, AZT stops reverse transcription.

1 minute 46 seconds

HIV life cycle

How HIV infects a cell and replicates itself using reverse transcriptase and the host's cellular machinery.

4 minutes 52 seconds

Protease inhibitors

Protease inhibitors prevent maturation of viral proteins inside HIV particles.

1 minute 6 seconds

U.S. AIDS epidemic

A visual representation of the U.S. AIDS epidemic from 1981 to 1997. Each dot represents 30 cases.

31 seconds

From the 1999 Holiday Lectures — 2000 and Beyond: Confronting the Microbe Menace

Bacterial Conjugation

Bacteria can transfer genetic material, and thus drug resistance, to other bacteria via conjugation.

23 seconds

E. coli Infection Strategy

Watch this animation to see the molecular tricks that an infectious strain of Escherichia coli uses to infect your gut.

2 minutes 52 seconds

Intracellular Infection by Salmonella

In this animation, you can see how one S. typhimurium invades an epithelial cell of the intestinal tract, survives the intracellular defense mechanisms of the host cell, and multiplies.

1 minute 18 seconds

Recombination of Viral Genome

When two different strains of influenza infect a single cell, their genetic material can mix freely, resulting in a new third strain of influenza.

3 minutes 5 seconds

Viral Lifecycle

Delivering a single virus to a cell allows the virus to infect the cell, replicate, and give rise to many progeny viruses. These viruses can then infect many neighboring cells.

1 minute 8 seconds