3. Label the pre-treated petri dish with the appropriate information, then pour the nutrient sample mix into the bottom half of the dish. The nutrient will not gel unless the correct half of the specially pre-treated petri dish is used.

4. Ensure the petri dish is positioned the right way up on a level surface, for 45-60 minutes. This is the time required for the nutrient to gel. When gel has set, invert plates for incubation.

5. Incubation:- Easygel will work quite effectively when incubated at room temperatures of between 20 to 24°C, however the bacteria will grow faster at higher temperatures in the range of 30 to 35°C. Incubate for 24 hours at 35°C or for 48-72 hours at room temperature.

6. Tips on incubation:- When incubating at "room temperature", find the warmest place in the building, (e.g. on top of the hot water system is a good spot). To elevate temperatures a simple "incubator" can be constructed using a cardboard box approximately 300mm long by 200mm wide by 300mm high lined with aluminium foil or the like and a free standing desk or reading lamp to provide the necessary warmth. Place a thermometer in the box and position the lamp directly over the centre and level with the top of the box. Temperature adjustments can be made by varying the height of the lamp or the strength of the bulb within the lamp. Shield the plates so that they are not directly exposed to the light. Do not locate the lamp too close to the dishes as this will cause browning of the media. Test the set up prior to inserting the plates to ensure the desired temperature has been achieved.

7. Reading Results:- Each bacterial colony on or in the medium represents one bacterial cell in the original sample. For example, assuming you used a 2 ml sample and you counted 50 colonies, this indicates approximately 25 bacteria per ml of the original sample.

8. It is essential to obtain countable numbers of colonies in/on the media. To achieve this, it may be necessary to use as little as 0.1 ml of sample or even I in 10 or 1 in 100 dilutions of that sample in the case of samples with large numbers of bacteria present.

9. Easygel Coliform medium allows growth of coliform bacteria but inhibits the growth of non-coliform bacteria. Coliform bacteria include E. coli, Citrobacter, Klebsiella Enterobacter and all form blue green colonies in/on Easygel Coliform media. All coliform bacteria are members of the family Enterobacteriaceae, defined as Gramnegative, non-spore-forming rods which ferment the sugar lactose with the formation of acid and gas.

10. Many coliforms are normally found in soil and in water, and do not necessarily indicate the presence of faecal contamination. But Escherichia coli (E. coli) is one of the principal bacteria in the mammalian intestinal tract and its presence in food or water indicates faecal contamination. It should be stressed that E. coli are part of the normal bacterial gut flora, and relatively few strains of E. coli cause disease.