Dual-Antibiotic Selection of Transformants: Isolates colonies harboring plasmids or genomes conferring resistance to 50 µg/mL kanamycin and 10 µg/mL tetracycline in Escherichia coli, leveraging LB (1% tryptone, 0.5% yeast extract, 1.0% NaCl, 1.5% agar) for robust growth.

Two-Plasmid Co-Selection: Maintains co-transformed constructs (e.g., expression + helper/replicase or CRISPR + guide vectors) requiring simultaneous KanR and TetR in Escherichia coli.

Clonal Isolation and Colony Screening: Streaks and single-colony purification under dual selection prior to downstream colony PCR, minipreps, or sequencing.

Conjugation/Mating Selections: Selects transconjugants carrying kanamycin- and tetracycline-marked elements after bacterial mating experiments in Escherichia coli.

Library Maintenance: Sustains combinatorial or barcoded libraries where vectors or hosts require both KanR and TetR markers.

Transformation Efficiency and CFU Enumeration: Quantifies colony-forming units for dual-resistant constructs on selective LB agar.

Chromosomal Integration Verification: Confirms insertion events that introduce kanamycin and tetracycline resistance cassettes in Escherichia coli.

Plasmid Stability Assays: Monitors retention of dual-resistance plasmids during passaging on selective solid medium.