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.
The bacteria in the yogurt is not harmful; however, it is possible for other bacteria to grow on the agar plates. For that reason, make sure to follow all the safety guidelines in the Experimental Procedure.Be sure to dispose properly any plates with bacteria when the experiment is over. Stack the plates and flip them so that they are upside down (with the agar on the top of each plate). 2  Arrange a tea light and the plates on the cutting board so that the bowl can cover them when it is upside down. 3  The tea light can go on top of the stack of plates or to the side of them.