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11: Appendix I- Antibiotics and Color Coding

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  • Page ID
    79500

    • Nathan Reyna, Ruth Plymale, & Kristen Johnson
    • Ouachita Babtist University & University of New Hampshire
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    LB Plates plus antibiotics (color coding)

    Green = LB + Ampicillin100*

    Black = LB + Chloramphenicol35**

    Blue = LB + Kanamycin50***

    Red = LB + Tetracycline10****

    Antibiotic Selection

    Ampicillin (Amp/A) A derivative of penicillin that kills growing cells by interfering with bacterial cell wall synthesis. The resistance gene (bla) specifies a periplasmic enzyme, \(\beta\)-lactamase, which cleaves the \(\beta\)-lactam ring of the antibiotic.

    *Working concentration 100µg/mL; freezer stock 100mg/mL (in water)

    Chloramphenicol (Chlor/C) A bacteriostatic agent that binds to the 50S subunit of the ribosome and blocking peptidyl transferase and inhibiting peptide bond formation. The resistance gene, chloramphenicol acetyltransferase (cat), specifies an enzyme that renders the antibiotic incapable of binding to the ribosome.

    **Working concentration 35µg/mL; freezer stock 35mg/mL (in EtOH)

    Kanamycin (Kan/K) A bactericidal agent that binds to 70S ribosomes and causes misreading of messenger RNA. The resistance gene (kan) specifies an enzyme (aminoglycoside phosphotransferase) that modifies the antibiotic and prevents its interaction with ribosomes.

    ***Working concentration 50µg/mL; freezer stock 50mg/mL (in water)

    Tetracycline (Tet/T) A bacteriostatic agent that binds to the 30S ribosome and disrupts codon and anticodon interactions. The resistance gene (tet) specifies a multimeric transporter protein that participates in the rapid efflux of tetracycline from the bacterial cell rendering it incapable of accessing the ribosomes.

    ****Working concentration 10µg/mL; freezer stock 10mg/mL (in water)

    This page titled 11: Appendix I- Antibiotics and Color Coding is shared under a not declared license and was authored, remixed, and/or curated by Nathan Reyna, Ruth Plymale, & Kristen Johnson.