Answer

Mix 1.5 g of agar with 10 ml of water into a paste. Slowly add more water with stirring until the volume is 100 ml. Heat the mixture on a boiling water bath to 95 °C in the required container. This preliminary heating can be omitted if the agar will then be sterilised, unless it is necessary to decant the agar into smaller containers prior to autoclaving.
 NOTE: this agar does not include any nutrients and can be used as a base for ading specific nutrients to. On its own it will not sustain growth of microbial cultures.