Description
In research settings, cephalothin sodium is commonly incorporated into agar plates or liquid media to suppress the growth of sensitive Gram-positive and certain Gram-negative bacteria, enabling selective isolation, plasmid maintenance studies, and antimicrobial susceptibility testing.
Its well characterized beta lactam mechanism and predictable activity profile make it a reliable tool for microbial selection and experimental design.
Cephalothin sodium is a first generation cephalosporin antibiotic widely used in molecular biology and microbiology as a selective agent for bacterial culture. It functions by inhibiting bacterial cell wall synthesis through binding to penicillin binding proteins, thereby blocking peptidoglycan cross linking and leading to cell lysis in susceptible organisms.
Key Features and Advantages
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Beta Lactam Mechanism of Action: Inhibits bacterial cell wall synthesis by targeting penicillin binding proteins, leading to effective suppression of susceptible bacterial strains.
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Selective Pressure in Culture: Provides defined selective conditions in microbiological media, supporting controlled growth of resistant strains while inhibiting non resistant contaminants.
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Broad Laboratory Utility: Active against many Gram-positive bacteria and some Gram-negative organisms, making it useful for general microbiology applications.
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Water Soluble Sodium Salt Form: Readily dissolves in aqueous buffers and culture media, simplifying preparation of stock solutions and antibiotic containing plates.
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Well Characterized Activity Profile: As a first generation cephalosporin, cephalothin has extensively documented antimicrobial properties, allowing reproducible experimental outcomes.
Common Applications and Usage Notes
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Selective Media Preparation: Added to agar or broth to inhibit susceptible bacteria during strain isolation or contamination control.
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Antimicrobial Susceptibility Testing: Used in disk diffusion or broth dilution assays to evaluate bacterial resistance profiles in research studies.
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Beta Lactam Resistance Studies: Applied in experiments investigating beta lactamase production, resistance mechanisms, or mutation frequency.
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Microbial Physiology Research: Utilized to study cell wall synthesis, stress responses, and lysis mechanisms in susceptible bacterial species.
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Contamination Control in Mixed Cultures: Helps suppress unwanted background organisms in laboratory cultures when resistance markers are present.
Practical Tips
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Stock Solution Preparation: Prepare fresh aqueous stock solutions using sterile water and filter sterilize before storage to maintain potency.
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Avoid Repeated Stock Freeze-Thaw Cycles: Aliquot stock solutions to preserve antibiotic activity over time.
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Storage/Handling: Store at 4°C. Protect from light.
