Culturing microbes (required practical): Cell biology

• Binary fission


  How bacteria asexually reproduce

  
• Colonies


  A visible mass of many bacteria

  
• Nutrient broth solution


  A liquid food culture media to grow bacteria

  
• Agar gel plates


  A solid food culture media to grow bacteria

  
• Aseptic technique


  A way of preventing contamination when growing bacteria

  
• Petri dish


  A glass or plastic dish where bacteria are grown on agar

  
• Inoculating loop


  A sterile looped piece of wire which can transfer bacteria between culture media

  
• Incubator


  A machine with a set temperature to grow bacteria

  
• Contamination


  When unwanted bacteria or other microorganisms grow in the culture media

  
• Culture media


  A liquid or solid food source to grow bacterial cultures in
• Antiseptic


  A substance which kills bacteria and other microorganisms
• Antibiotic


  A medication which is used to kill specific bacteria

  
• Sterilisation


  A method of removing microorganisms from surfaces usually by means of chemicals or heat

  
• Disinfectants


  A substance which prevents the growth of bacteria and other microorganisms

  
• Zone of inhibition


  An area of media where bacteria cannot grow that shows the effectiveness of a disinfectant or antibiotic

  
• Diameter or area of clear zone

  The dependent variable or factor that is measured in this experiment to investigate the effect of disinfectants

  
• Type or concentration of disinfectant


  The independent variable or factor that is changed in this experiment to investigate the effect of disinfectants
• Temperature, time, volume, concentration


  Possible variables that can be controlled to make sure the experiment is a fair test
• Experimental procedure


  Multiple sterile discs should be dipped into different disinfectants or different concentrations of disinfectant, after which they should be carefully placed on agar and incubated with bacteria
• Expected results


  The more effective the disinfectant, the larger the area of the zone of inhibition

  
• Control sample


  A disc soaked with water and no disinfectant on can be used as a control to compare with discs that have been dipped in disinfectant