Selection of Rifampicin-Resistant Colonies: Isolates colonies carrying rifampicin resistance on LB agar (1.0% Tryptone, 0.5% Yeast Extract, 1.0% NaCl, 1.5% Agar) with 100 µg/mL rifampicin.

Plasmid/Chromosomal Marker Maintenance: Maintains strains harboring rifampicin-resistance cassettes or rpoB mutations under selective pressure.

Conjugation and Mating Experiments: Counterselects rifampicin-sensitive donors to recover rifampicin-resistant transconjugants.

Mutation Rate and rpoB Screening: Screens for mutations in rpoB and measures spontaneous mutation frequencies in Escherichia coli and related bacteria.

Strain Construction and Mapping: Uses rifampicin resistance as a selectable genetic marker during strain engineering workflows.

Mixed Culture Selection: Enriches rifampicin-resistant target strains while suppressing rifampicin-sensitive background flora.

Transcription Studies: Selects rifampicin-resistant hosts for experiments probing RNA polymerase function and rifampicin sensitivity.

Quality Control and Contamination Monitoring: Monitors culture purity by selecting for intended rifampicin-resistant production strains.

Routine Maintenance of Laboratory Stocks: Preserves rifampicin-resistant clones of E. coli on ready-to-use sterile 100 mm plates (20 per sleeve).