Lexic.us

Definition of Gram stain

1. Noun. A staining technique used to classify bacteria; bacteria are stained with gentian violet and then treated with Gram's solution; after being decolorized with alcohol and treated with safranine and washed in water, those that retain the gentian violet are Gram-positive and those that do not retain it are Gram-negative.

Medical Definition of Gram stain

1. A method of staining bacteria using a violet stain. The gram staining characteristics (denoted as positive or negative) can assist in the identification of the offending bacteria. A heat fixed bacterial smear is stained with crystal violet (methyl violet), treated with 3% iodine/potassium iodide solution, washed with alcohol and counterstained. The method differentiates bacteria into two main classes, gram-positive and gram-negative. Certain bacteria, notably mycobacteria, that have walls with high lipid content show acid-fast staining the stain resists decolouration in strong acid. (27 Sep 1997)

Lexicographical Neighbors of Gram Stain

Literary usage of Gram stain

Below you will find example usage of this term as found in modern and/or classical literature:

1. Surgery, Gynecology & Obstetrics by The American College of Surgeons, Franklin H. Martin Memorial Foundation (1922)
"January 24, 1920, smears gram stain—j-gram positive diplococci and large ... January 28, 1921, smears—gram stain^gram positive bacilli and diplococci, ..."

2. Niosh Manual of Analytical Methods: Sampling and Analytical Methods for edited by Peter M. Eller (1994)
"Two examples of differential stains are the Gram stain and the acid-fast stain. The mechanism of the Gram stain may be explained on the basis of physical ..."

3. Urology: Diseases of the Urinary Organs, Diseases of the Male Genital Organs by Edward Loughborough Keyes (1917)
"This we find in the reaction of the gonococcus to the Gram stain. ... Hence, when the Gram stain is applied, a thorough washing with alcohol leaves the ..."

4. Bacteriology, General, Pathological and Intestinal by Arthur Isaac Kendall (1921)
"Gram stain.1—A most important differential method of staining bacteria is ... the principle of the Gram stain and has drawn the following conclusions with ..."

5. The Journal of Infectious Diseases by Infectious Diseases Society of America, John Rockefeller McCormick Memorial Fund, John McCormick Institute for Infectious Diseases (1914)
"mental evidence tends to show that by long contact with serum, the bacteria become sufficiently coated with albumin to respond abnormally to the Gram stain. ..."

6. Preventive Medicine and Hygiene by Milton Joseph Rosenau, George Chandler Whipple, John William Trask, Thomas William Salmon (1921)
"... stain, gram stain. The absence of diphtheria bacilli must not be assumed if negative results are obtained, as they often pass unrecognized if mixed with ..."

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