Growth media and methods
Start with the big picture
Culture work begins with aseptic technique, including sterilizing instruments and surfaces, to limit contamination. Media are selected according to the task: solid agar supports isolation, while broth can enrich growth; enriched, selective, and differential media provide nutrients, inhibit some organisms, or reveal traits such as lactose fermentation and hemolysis. Transport media preserve viability without encouraging growth. Culture conditions also vary: anaerobes need reduced-oxygen environments, capnophiles grow with added carbon dioxide, and some organisms require specialized media or living cells. Batch-culture growth phases provide context for choosing when to harvest cultures for assays. Together, these principles connect specimen handling, organism recovery, and interpretation.
What you'll learn
- Explain how aseptic technique and sterilization reduce contamination risks.
- Distinguish solid, liquid, enriched, selective, differential, and transport media by purpose.
- Relate batch-culture growth phases to assay harvest timing.
- Identify specialized culture requirements for selected microorganisms.
- Describe how culture conditions support recovery and interpretation.
Continue your study
Work through the complete notes and reinforce the topic with the study tools available in the full lesson.
