Comenius Project London Exchange Visit

1. Comenius ProjectLondon Exchange Visit Leyton Sixth Form College Microbiology Welcome to students and teachers from Bochum and Szolnok 18-22 April 2005

2. 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. Microbiology at Leyton Introduction (1) Comenius – Leyton Sixth Form College – April 2005

3. 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. Microbiology at Leyton Introduction (2) Comenius – Leyton Sixth Form College – April 2005

4. 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. Microbiology at Leyton Introduction (3) Comenius – Leyton Sixth Form College – April 2005

5. 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. Microbiology at Leyton Aseptic Techniques (1) Comenius – Leyton Sixth Form College – April 2005

6. 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. Microbiology at Leyton Aseptic Techniques (2) Comenius – Leyton Sixth Form College – April 2005

7. 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. Microbiology at Leyton Aseptic Techniques (3) Comenius – Leyton Sixth Form College – April 2005

8. 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. Microbiology at Leyton Aseptic Techniques (4) Comenius – Leyton Sixth Form College – April 2005

9. 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 Microbiology at Leyton Safety (Key Points) Comenius – Leyton Sixth Form College – April 2005

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