Gram's method
Gram staining

Gram staining and culture gave negative results.

Gram-positive bacteria are those that are stained dark blue or violet by Gram staining.

Along with cell shape, Gram staining is a rapid diagnostic tool of use to group species of bacteria.

The listeria are rod-shaped bacteria and become positively stained when subjected to Gram staining.

Gram staining is also less reliable in particular infections such as listeriosis.

For example, crystal violet stains only Gram-positive bacteria in Gram staining.

Gram staining is used to determine gram status to classify bacteria broadly.

Crystal violet is an important component in Gram staining.

While Gram staining is a valuable diagnostic tool in both clinical and research settings, not all bacteria can be definitively classified by this technique.

There is no connection between the shape of a bacterium and its colors in the Gram staining.