Selection of Ampicillin-Resistant Transformants: Isolates colonies of Escherichia coli carrying bla (β-lactamase) plasmids after transformation.

Plasmid Maintenance and Propagation: Maintains selective pressure for plasmid-bearing Escherichia coli during routine subculturing.

Colony Screening and Picking: Grows individual recombinant colonies for downstream minipreps, PCR, or sequencing.

Blue-White Screening: Enables α-complementation screening on LB/Amp plates when supplemented with IPTG/X-gal.

Transformation Efficiency Assays: Plates serial dilutions to quantify CFUs following chemical or electroporation transformation of Escherichia coli.

Library Plating: Distributes plasmid libraries or mutagenesis pools for colony picking under ampicillin selection.

Protein Expression Strain Selection: Selects recombinant Escherichia coli expression strains harboring ampicillin-selectable vectors.

Replica Plating for Plasmid Stability: Assesses plasmid retention by comparing growth on selective vs. non-selective plates.

Glycerol Stock Preparation: Picks single selected colonies to start cultures for long-term cryostorage.

Teaching and Training Labs: Demonstrates antibiotic selection and basic cloning workflows using Escherichia coli.