Gram-positive bacteria show blue or purple after Gram-staining in a laboratory test. They have thick cell walls. Gram-negative bacteria show pink or red on staining and have thin walls. They release ...

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, ...

Urinary tract infections (UTIs) are common, but increasingly hard to treat because the bacteria that cause them are developing resistance to many antibiotics. Researchers headed by a team at the ...