gram stain
This term refers to a specific laboratory procedure rather than a general coloring process. It is used exclusively in clinical and research microbiology to provide a rapid preliminary identification of bacteria, which guides the initial choice of antibiotic treatment before more time-consuming culture results are available.
In professional medical reporting, the term is often used as a shorthand for the results of the test (e.g., "the gram stain showed cocci in clusters"). While "gram" refers to Hans Christian Gram, the inventor of the method, the term is treated as a compound noun in technical discourse.
Meanings
A differential staining technique used in microbiology to classify bacterial species into two large groups, Gram-positive and Gram-negative, based on the chemical and physical properties of their cell walls.
The technician performed a gram stain to identify the bacteria causing the infection.