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.
Gelidium is the preferred source for agars. Impurities, debris, minerals and pigment are reduced to specified levels during manufacture. Agar is a gel at room temperature, remaining firm at temperature as high as 65Â°C. Agar melts at approximately 85Â°C, a different temperature from that at which it solidifies, 32-40Â°C. This property is known as hysteresis. Agar is generally resistant to shear forces; however, different agars may have different gel strengths or degrees of stiffness.