Antibiotic Selection of AmpR Plasmids: Carbenicillin (100 µg/mL) selects bla-bearing constructs on LB (1.0% Tryptone, 0.5% Yeast Extract, 1.0% NaCl, 1.5% Agar) with 5.0% sucrose, reducing satellite colonies versus ampicillin.

Transformation and Recovery: Plate heat-shock or electroporated E. coli on selective media; 5% sucrose provides osmoprotection to improve recovery of stressed cells and spheroplasts.

Plasmid Maintenance and Propagation: Routine growth of AmpR plasmid-bearing colonies in cloning and expression strains for downstream minipreps and glycerol stocks.

Colony Screening: Rapid colony PCR or insert verification from carbenicillin-selected colonies prior to liquid culture scale-up.

sacB-Based Counter-Selection Workflows: Use 5% sucrose to select against sacB during allelic exchange/recombineering in Gram-negatives while maintaining bla-marked intermediates.

Conjugation and Transduction Selection: Select exconjugants/transductants carrying beta-lactam resistance in species such as E. coli, Pseudomonas aeruginosa, and Vibrio cholerae.

Expression Clone Screening: Initial selection of AmpR expression constructs in E. coli prior to small-scale induction tests.

General Selective Plating: Enumeration and isolation of antibiotic-resistant colonies while sucrose supports osmotic stabilization for sensitive strains.