Plasmid Selection and Maintenance: Selection of beta-lactam–resistant clones and stable maintenance of bla-bearing plasmids in E. coli.

Transformation Screening: Post-transformation plating (chemical or electroporation) to recover and identify antibiotic-resistant transformants.

Blue-White Screening: Alpha-complementation screening of recombinant clones when supplemented with X-gal/IPTG.

Colony Isolation and Purification: Streaking for single colonies to obtain clonal isolates for downstream workflows.

CFU Enumeration: Quantifying transformation efficiency and viable counts of antibiotic-resistant cells.

Clone Verification for Minipreps: Picking colonies for plasmid prep, restriction analysis, and sequencing.

Library Selections: Enrichment of pooled cloning libraries (e.g., CRISPR gRNAs, mutant libraries) carrying bla markers.

Protein Expression Workflow Prep: Selecting recombinant expression strains prior to induction in E. coli.

Conjugation/Mating Selections: Selecting donor or recipient strains that harbor beta-lactam resistance cassettes.

Non-E. coli Gram-Negative Selections: Maintenance of bla-marked plasmids in organisms such as Agrobacterium tumefaciens or Pseudomonas aeruginosa, where susceptible.