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

If you've kept up with the news lately, you've probably heard dire warnings about avian flu, or bird flu. In this article, we'll review the basics of how viruses and influenza work, and we'll learn the answers to these and other questions about avian flu, including whether it is likely to cause a global flu epidemic.

By Tracy V. Wilson

While most flu sufferers moan and groan for about a week and then return to work, the flu season creates more than just discomfort and a costly loss of work days.

By Stephanie Watson

We hear about them on the news and we listen to politicians argue for and against them using them to treat disease. Learn all about stem cells and the research, challenges and controversy that surround them.

By Stephanie Watson & Craig Freudenrich, Ph.D.

HIV continues to be a major global public health issue, having claimed more than 35 million lives so far.

By Kevin Bonsor & Oisin Curran

Hand sanitizers can only get you so far in preventing a viral infection. Scientists are discovering how visible light can be used to destroy viruses. Learn about the laser technique and what it means for the future.

By Jacob Silverman & Patrick J. Kiger

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

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

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

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

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

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

Cell suicide sounds unpleasant, but this programmed cell death is the reason your fingers and toes are no longer webbed. What's the story behind apoptosis, and what does it have to do with curing disease?

By Molly Edmonds

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

Your body temperature has an important role to play in fighting off infections from viruses like the flu. Here's how it works.

Learn about weight gain and the processes going on in your cells.

By Craig Freudenrich, Ph.D.