Cellular & Microscopic Biology

In science, people commonly use the terms "hypertonic" and "hypotonic" when describing the concentration of solute particles in solutions. But what exactly is the difference when it comes to hypertonic vs. hypotonic solutions?

By Marie Look

Your phone might look clean, but in reality, it's harboring germs, viruses and bacteria. So stop doomscrolling in the bathroom.

By Primrose Freestone

It's kind of amazing that no two fingerprints are alike, not even for identical twins! But why is that?

By Alia Hoyt

The Ophiocordyceps unilateralis fungus makes a mockery of ant free will. But how does it take over the ant body to control its host?

By Jesslyn Shields

New studies suggests your gait may be able to predict something deeper than just a temporary mood.

By Jesslyn Shields

Worried that we're running out of effective antibiotics? Never fear. Scientists are plundering cockroach brains and other surprising sources to create new lifesaving medications.

By Patrick J. Kiger

Lots of Americans believe that getting the flu is no worse than getting a cold. Or that the flu vaccine can give them flu. We separate truth from fiction.

By Patrick J. Kiger

When you get sick, your illness can be caused by several different factors. Learn why you get sick at HowStuffWorks.

By Molly Edmonds

The results of three recent studies show that an uncircumcised man is twice as likely to contract AIDS from an infected woman as is a circumcised one.

By Julia Layton

Phone calls, e-mails, sign language, friendly shouts -- this is how we communicate in our daily lives. Bacteria, some of the tiniest organisms on Earth, have a different way of talking.

By Molly Edmonds

For something too small to be detected by an ordinary microscope, viruses pack a big punch. We all know they can wreak havoc on the body, but how do they do it?

By Molly Edmonds

Pasteurization is the process of removing harmful pathogens from various types of food. How was this process discovered?

By Carol White

You may be familiar with the medieval "Black Plague," but did you know that bouts of plague still break out today? Find out what causes an outbreak, why plague still exists and how the plague has influenced history.

By Tracy V. Wilson & Alia Hoyt

The journal "Nature" recently published a paper describing how a cell transplant had allowed blind mice to see again. What does this mean for humans?

By Tracy V. Wilson

You've heard it on the lips of every newscaster and seen it in the pages of every newspaper and Web site: swine flu. Just how worried should we be about the 2009 version of the H1N1 virus?

By Molly Edmonds

Biofilms form when single microorganisms attach to a hydrated surface and undergo a "lifestyle switch." But why should we care about biofilms?

By Marianne Spoon

Herd immunity means that after a certain percentage of a population is immune to a disease, the whole population is. This is usually achieved through vaccination but some are not convinced.

By Alia Hoyt & Molly Edmonds

Are you the first to complain when it's too hot or too cold at work? Extremophiles have news for you: Suck it up. These hardy microbes make most of us humans seem like whimpering Goldilocks, and studying them may tell us more than you might imagine.

By Jacob Silverman & Desiree Bowie

Nearly every cell in your body has the same DNA. It's the hereditary material located your cells' nucleus. But what does it do and why is it so important to all living beings?

By Craig Freudenrich, Ph.D. & Jennifer Walker-Journey

Bacteria are both friend and foe to humanity. They cause and cure health problems, make rotting food stink and give sourdough its delicious taste. Find out how these countless tiny microbes accomplish all of this and more.

By Marianne Spoon

You won't find some of history's biggest killers on this list, but you will find at least one disease that will make you want to bite something and another that might make you break out in "elevated pustules." Curious yet?

By Garth Sundem

Viruses, viroids and prions are microscopic, infectious particles with a common, despicable goal — but the way each goes about achieving that goal is different.

By Debra Ronca

Your body replaces billions (with a b!) of cells every day. In about 100 days, 30 trillion be replaced, but does that mean you're a new person, too?

By Chris Opfer & Allison Troutner

Researchers are working on ways to engineer viruses to attack cancer cells, killing the disease without radiation, medicine or surgery. How do the viruses know what to kill?

By Josh Clark

How can spam e-mail help fight HIV? Find out how spam e-mail and HIV are linked and learn about new methods for HIV treatment.

By Josh Clark