Gram stain
Tinción de Gram
- Date
- 1884 · confidence high
- Place
- Berlin, Germany
- Credited to
- Hans Christian Gram
- Field
- Life & health
What it is
Danish bacteriologist Hans Christian Gram devised, in the morgue of Berlin's city hospital, a differential staining technique that classifies bacteria as gram-positive or gram-negative according to their cell wall structure, originally intended only to improve the visibility of bacteria in lung tissue.
Gram published the technique in 1884 without attaching much importance to it; over time it became one of the most widely used tests in microbiology.
What it led to
- the fundamental bacteriological classification into gram-positive and gram-negative
- a basic diagnostic tool in clinical microbiology
- initial guidance for antibiotic treatment based on bacterial wall type