1 A do-it-yourself approach for basic basement steps starts around $250-$350 for materials, and takes about 3-4 hours. 2  That's with standard lumber, such as pine; costs can go much higher with more expensive wood, such as oak.
Pour enough melted agar into each sterile plastic petri dish to cover the bottom - about 1/8 to 1/4 deep. Replace the lid immediately. Place agar plates on a counter top to cool and set. Agar medium will set like stiff gelatin at room temperature. The agar medium is now ready for storage or use.
Preparing Agar Agar. 1  1. Find Agar and decide which form works best for you. Agar usually comes in three forms: powder, flakes, or a bar. 2  2. Add Agar to the liquid and mix with a whisk. The firmness of the gel is determined by the amount of Agar you add. 3  3. Bring the solution to a boil and allow it to simmer.