Step by step guide to using Coliscan and Total Count Easygel.

Home page.

Easygel kits are an easy way to test for bacteria in water. They can be used by folks at home, students, teachers, businesses and professionals. There are two types of kits; Coliscan Easygel for E coli and coliforms and, Total count Easygel for total aerobic bacteria. These test the 3 groups used by the Australian Drinking Water Guidelines to assess water quality.

Not only do these kits detect the bacteria most critical for water quality but they show actual colonies. So by adjusting for sample size, the actual numbers of colonies for a given volume can be calculated so you know exactly what levels of bacteria are present in your water.

Kits come with background information describing the technology, full printed instructions and colour guide.

Here is the basic step by step process for using the kits.

Thaw the media bottle in a little warm water. Remember bacteria are very small so it's a good idea to wash your hands before getting a sample. Work in a clean spot. Don't touch anywhere on the kits where it might contaminate the sample.
Collect a sample in the sterile bottle. To avoid getting any unwanted bacteria keep fingers away from the neck of the bottle and hold the cap in one hand. You can also gently dip the bottle into a dam or spring.
Use the sterile dropper to transfer a sample into the thawed media bottle. Use up to 5 ml for fairly clean eg town water, but use less, say 2.5 ml for a rainwater tank or protected creek or spring and 1 ml for an unprotected water supply eg a dam or creek.
Recap the media bottle and gently swirl the bottle to mix the sample. Take a petrie dish that comes in the kit. Lift the lid (the wider part) a little then pour in the media. Put the lid on and leave the dish undisturbed for 45 - 60 mins.
Carefully tilt the dish to check if the media has set. If so then tip it upside down (wider part on the bottom). This is to stop condensation from dripping onto the growth media surface.
Place the dish somewhere warm and dark such as a kitchen cupboard. Around 25 to 28 deg C will give good growth. In winter or in a cool climate look for a warm spot in the house. A heated seedling raiser makes a good cheap incubator. Keep the dishes covered or away from strong light.
Some colonies may appear from 20 - 24 hrs. Count the colonies before 48 hrs. Use the color guide to identify colonies. To help with the count slowly move a ruler behind the dish and count from side to side. The instructions will tell you how to work out how many bacteria per 100 ml of sample water. If there are more colonies that can be easily counted then you may have to use the grid method. Click here for instructions. Colonies on the Total count media are pale or colourless.

Congratulations you've done it!

Your instructions will show you what colours to look for but here is the colour guide again for the E coli / coliforms kits Coliscan Easygel colour guide.

Check out our other help pages for information on choosing and using the Easygel test kits How to test your water for bacteria, Coliscan Easygel kits and Choosing bacteria test kits.

Compare your results with the figures for bacteria levels typically found in different situations in our notes What do your water test results mean?

Return to top