Comenius Project London Exchange Visit

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Comenius ProjectLondon Exchange Visit

• Leyton Sixth Form College
• Microbiology
• Welcome to students and teachers from Bochum and
  Szolnok
• 18-22 April 2005

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Introduction (1)
Microbiology at Leyton

• Microbiology is the study of micro-organisms.
• Micro-organisms are classified into a number of
  groups the main three being
• Viruses
• Bacteria
• Fungi
• Viruses are too small to be studied in a college
  laboratory but we are able to look at bacteria
  and fungi by using culture techniques.
• Culturing means growing the micro-organism and
  causing it to reproduce and requires a culture
  medium.

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Introduction (2)
Microbiology at Leyton

• Culture media are all based on a solution which
  contains all the nutrients necessary for the
  growth of the particular organism or organisms
  being cultured.
• The medium also needs to be adjusted to the
  correct pH.
• Media can be solid (achieved by adding agar which
  solidifies at 400C) or liquid.
• We will be using solid agar over the next two
  sessions but will show you the use of liquid
  media in a bioreactor on Friday.

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Introduction (3)
Microbiology at Leyton

• We will be using a non-selective complex medium
  called nutrient agar which will allow the growth
  of almost any micro-organism.
• A complex medium is based on natural products
  such as meat or yeast extracts whereas a
  synthetic medium is made of of individual
  chemicals.
• A selective medium is adjusted in some way such
  as by choosing an unusual pH so that it only
  allows the growth of one or a few species of
  organisms.
• Finally, it is necessary to incubate the culture
  at a suitable temperature and this is usually
  between 200C and 370C.

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Aseptic Techniques (1)
Microbiology at Leyton

• We will be carrying out seven aseptic techniques
  in the next two sessions.
• Aseptic means carrying out the technique without
  contaminating either the culture or the
  laboratory environment.
• For safety reasons we will attempting to grow
  either yeast or milk bacteria. We are not allowed
  to culture micro-organisms obtained from human
  secretions or any pathogenic organism.
• Pathogenic means disease-causing.

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Aseptic Techniques (2)
Microbiology at Leyton

• The handout gives details of the seven techniques
  which are
• 10.4 Pouring an agar plate
• 10.5(a) Preparing a streak plate
• 10.5(b) Streaking a plate
• 10.6 Preparing a pour plate
• 10.7 Inoculating an agar slope
• 10.8 Inoculating an agar deep (or stab culture)
• 10.9 Preparing a confluent or spread plate
• Inoculation is the name given to transferring the
  culture to the medium and usually involves a
  sterilised instrument such as a loop.

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Aseptic Techniques (3)
Microbiology at Leyton

• In both sessions you will work in groups of three
  (one student from each country) but all three in
  each group will try and carry out an individual
  experiment.
• In Session 1 you will carry out 10.4, 10.5(a) and
  10.5(b).
• In Session 2 where there will be more time, you
  will carry out 10.6, 10.7, 10.8 and 10.9.
• Each session of practical work will start with a
  video where David Wyatt will demonstrate the
  techniques and the video will also show our AVCE
  students carrying out the techniques.

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Aseptic Techniques (4)
Microbiology at Leyton

• Both the video and handout goes over the safety
  precautions which must be followed to avoid
  contamination of either the culture or the
  laboratory.
• The safety precautions also protect you from
  contamination or other danger and must be
  followed.

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Safety (Key Points)
Microbiology at Leyton

• To ensure your own safety and that of those
  working with you it is particularly important to
  do the following
• Wear safety glasses
• Wear a lab coat
• Securely seal all plates and tubes
• Label all plates and tubes clearly
• Sterilise inoculating instruments both before and
  after use
• No hand to mouth operations such as eating and
  drinking

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