A NEW method of providing dyes for some of the commoner staining procedures has been developed and tested. A small volume of the required dye solution is prepared according to the appropriate formula.

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-positive bacteria have thick cell walls. A Gram stain test, which involves a chemical dye, stains the bacterium’s cell wall purple. On the other hand, gram-negative bacteria stain pink instead.

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, ...