Bacterial Plasmid Selection: Selects for spectinomycin-resistant plasmids in Escherichia coli and Agrobacterium tumefaciens during cloning and strain construction.

Plasmid Maintenance: Maintains selection pressure for specR vectors and BACs in routine culture to prevent plasmid loss.

Dual Antibiotic Selection (aadA): Enables selection with spectinomycin and streptomycin when using aadA-based resistance cassettes.

Cyanobacterial Engineering: Used for genomic integration and plasmid selection in Synechocystis and Synechococcus.

Mycobacterial Genetics: Supports selectable marker use in species such as Mycobacterium smegmatis for cloning and mutagenesis.

Agrobacterium Vector Work: Selects specR binary vectors and maintains engineered Agrobacterium strains for plant transformation workflows.

Chloroplast/Plastid Transformation: Selects aadA-marked transformants in plant and algal plastids (e.g., tobacco, Chlamydomonas) using spectinomycin.