Definition

1. Noun:
   • A staining technique used to classify bacteria: Gram's procedure is a laboratory method for differentiating bacterial species into two large groups (Gram-positive and Gram-negative) based on the chemical and physical properties of their cell walls. The procedure involves staining bacteria with a crystal violet dye, treating with an iodine solution, decolorizing with alcohol or acetone, and counterstaining with a red dye such as safranin.

Usage

• Gram's procedure is a fundamental technique in microbiology.
• The results of Gram's procedure are critical for initial bacterial identification and guiding antibiotic therapy.
• Performing Gram's procedure correctly requires precise timing during the decolorization step.

Examples

• Noun:
  • The laboratory technician performed Gram's procedure on the clinical specimen.
  • The reliability of Gram's procedure depends on the age of the bacterial culture.
  • Students learned Gram's procedure in their introductory microbiology lab.

Advanced Usage

• "To be subjected to Gram's procedure": to have the staining technique applied.
  • The unknown isolate was subjected to Gram's procedure.
• "Results of Gram's procedure": the outcome (Gram-positive or Gram-negative) observed under a microscope.
  • The results of Gram's procedure indicated a Gram-negative rod.

Variants and Related Words

• Gram stain (n): A common synonym for Gram's procedure. It can refer to the technique itself or the final stained slide for viewing.
  • The Gram stain revealed purple cocci in clusters.
• Gram-positive (adj): Describing bacteria that retain the crystal violet stain and appear purple after Gram's procedure.
• Gram-negative (adj): Describing bacteria that do not retain the crystal violet stain, take up the counterstain, and appear pink or red after Gram's procedure.
• Gram reaction (n): The result (positive or negative) obtained from Gram's procedure.

Synonyms

• Gram staining: The act of performing the procedure.
• Gram's method: An alternative name for the technique.

Related Phrases

• Perform a Gram stain: To carry out Gram's procedure.
  • The first step is to perform a Gram stain on the sample.
• Visualize under microscopy: The step following Gram's procedure to see the results.
  • After completing Gram's procedure, the slide is visualized under oil immersion microscopy.

Noun

1. 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