A bout with a cold or the flu can really take you down. To stay healthy, you need to avoid nasty bugs. But that’s not always easy. Germs are everywhere, and there are plenty of ideas about how to get ...

Gram staining is one way scientists can identify bacteria. Gram-positive bacteria, such as Staphylococcus, appear blue or purple under a microscope when scientists apply a stain. Conversely, ...