There are many ways of classifying bacteria. One method is based on the cell membrane. In 1884, a bacteriologist named Christian Gram created a test that could determine if a bacterium had a thick, ...

Hans Christian Gram, the inventor of the Gram staining technique, was a pioneering biologist who devised the system of classification which led to as many as 30,000 formally named species of bacteria ...

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, ...