4 Pre-Poured Malt Yeast Agar Culture Slant Tubes 20 x 125 mm - 3/4 x 5" These pre-poured sterile (MYA) malt yeast agar media test tube slants, designed for culturing mushroom mycelium and storing the tissue for long periods of time Forest Organics offers many formulations that have been developed for the cultivation of mushrooms on a semisolid agar medium, agar is a seaweed derived compound that gelatinizes water. Nutrients are added to the agar / water base, in our lab we sterilize a mixture of malt, yeast, and agar. We pour the mixture in a glass test tube that contains a wooden stick that the mycelium can colonize increasing the time you can store the slant, we find this formula to facilitate, and promote healthy mushroom mycelium, this mixture is the most commonly used with the greatest success.