Bacterial Transformation and Selection: Selection of ampicillin‑resistant transformants of E. coli carrying β‑lactamase–expressing plasmids.

Plasmid Maintenance and Expansion: Routine propagation of AmpR plasmids in E. coli under selective pressure.

Colony Screening and PCR: Picking colonies for colony PCR/Sanger sequencing to verify inserts from AmpR cloning workflows.

Library Construction and Screening: Selection of recombinant DNA libraries (e.g., gDNA/cDNA, sgRNA) in AmpR E. coli hosts.

High‑Density Colony Arrays: QTray format supports high‑throughput arraying, replica plating, and robotic colony picking of AmpR strains.

CFU Enumeration and Viability: Quantifying viable AmpR E. coli after transformation or storage.

Phage Display/Phagemid Workflows: Growth and selection of AmpR phagemid‑bearing E. coli during library amplification steps.

Conjugation/Mating Selections: Post‑mating selection of recipient E. coli that acquired AmpR plasmids.

Glycerol Stock Recovery: Revival and re‑isolation of AmpR strains from frozen stocks to maintain plasmid integrity.

Quality Control of Ampicillin Resistance: Verifying AmpR phenotype and plasmid retention in engineered E. coli strains.