Welcome! In this video you'll be shown how to prepare an agar mixture for plating C. elegans worms. This particular recipe is called the nematode growth medium or NGM for short. To produce 250 milliliters of liquid agar solution for the first phase you will need the following ingredients.

0.75 grams of NaCl, 0.625 grams of bactropeptone and 4.25 grams of agar agar. Weigh the quantities for each ingredient, mix with water and then you autoclave for 20 minutes.

In order to homogenize the mixture so that it has a consistent colour and opacity, you may microwave the bottles, not allowing the mixture to become too hot to avoid the glass shattering. Do not let the microwave go for an entire cycle, please make sure to stop the microwave often to inspect the mixture. When microwaving the bottles, please ensure that you are wearing a face shield to protect your eyes and face.

We then allow the agar mixture to cool to 55 degrees Celsius. Afterwards we add the following ingredients to the mixture. 250 milliliters of cholesterol, 250 milliliters of magnesium sulphate and calcium chloride, 6.25 milliliters of KPO4 buffer and 0.5 milliliters of nystatin which is an antifungal.

The reason why we let the bottles cool down to 55 degrees is because nystatin degrades at 60 degrees, which obviously we don't want to happen. Once you have added your final ingredients, mix gently by stirring the bottle in your hand and then pour into your plates.

For larger plates use 30 milliliters of the agar mixture. Please allow the agar to solidify over a period of 24 to 48 hours in the plate at room temperature.