Selective Isolation of Gram-Negative Enterics: Enriches recovery of enteric Gram-negative rods from mixed clinical, environmental, or food samples while inhibiting Gram-positives.

Differentiation by Galactose Fermentation: Distinguishes galactose-fermenters (pink/red colonies) from non-fermenters (colorless) on a MacConkey base with 1.0% D-(+)-galactose.

Detection of Galactose-Fermenting Enterics: Aids recognition of organisms such as Escherichia coli, Klebsiella pneumoniae, and Enterobacter cloacae as galactose fermenters.

Isolation of Non-Fermenting Pathogens: Supports recovery of non-fermenters like Salmonella enterica, Shigella sonnei, and Pseudomonas aeruginosa as pale/colorless colonies.

Counterselection of Gram-Positive Bacteria: Bile salts and crystal violet suppress growth of Gram-positive flora to reduce background.

Gal Operon/Membrane Transport Screening: Phenotypic selection and verification of mutants or constructs affecting galactose uptake and metabolism.

Quality Control and Purity Checks: Routine streaking and subculture to verify culture purity and colony morphology of enteric isolates.

Environmental and Food Testing: Enumeration and profiling of Gram-negative contaminants with galactose fermentation readout.

Antibiotic Workflow Support: Colony isolation prior to susceptibility testing on a selective/differential medium.

Teaching and Training: Demonstration of carbohydrate fermentation and selective/differential plating principles in microbiology labs.