Most species of bacteria can be broadly divided into two groups, known as gram-positive and gram-negative. These categories ...

When bacteria retain the crystal violet dye during the Gram stain test, they are called Gram-positive bacteria. Learn more here.

Gram-positive and Gram-negative are types of bacteria. There are many different types of Gram-positive and Gram-negative bacteria. These bacteria cause a wide range of different health issues.

Gram-positive bacteria are bacteria with thick cell walls. In a Gram stain test, these organisms yield a positive result. Here’s why knowing whether the result is positive or negative is important.

Learn the differences between gram positive vs gram negative bacteria, including structure, stain results and examples of key bacterial species.

Gram positive bacteria are those that stain purple. They are usually non-pathogenic and their cell walls contain a thick layer of peptidoglycan.

Find out the differences between gram-positive bacillus and gram-negative bacillus and how they may affect health.

Learn the differences between gram positive vs gram negative bacteria, including structure, stain results and examples of key bacterial species.