20 custom mushroom slants for long term storage. Choose media type and the style tube. Light malt extract is most common media type for growing mushrooms.Other media types can have added nutrients for more robust growth or minimal nutrients for more restricted growth(water agar). Slants can have wood added to extend the storage life of the slant. Injectable slants will be able to receive liquid culture from a syringe in a sterile way to test of syringe is clean and store your culture. 15 ml tubes are good for storage as in they take up very little space. The 50 ml tubes are larger but are easier to get cultures out of with tubes. This item is made of agar and light malt extract.