*10X Stock Salts: CaCl₂.2H₂O, 6.0 g; MgSO₄.7H₂O, 2.0 g; dH₂O, 1000 ml

**1000X Stock Iron: Dissolve 0.75 g Na₂EDTA.2H₂O, 0.56 g FeSO₄.7H₂O and 0.02 g of Na₂MoO₄.2H₂O in 100 ml dH₂O

***10X Buffer: KH₂PO₄ 6.8 g/l; MOPS (3-(N-morpholino) propanesulfonic acid) 11.56 g/l.  Adjust pH to 6.5 with HCl. The buffer should be prewarmed to about 50^o C and added to the medium before plating to avoid clumping of the gellan gum.

Notes: 

- The medium is made by adding the first five ingredients plus gellan gum to make 900 ml. The buffer stock is added separately after autoclaving. Phytagel is a polysaccharide gum produced by "Pseudomonas elodea." It is solubilized during autoclaving but resolidifies at a higher temperature than agar. Therefore plates are poured at about 70^o C using a glove to protect the hand. Before spread plating Frankia, allow the surface to "harden" by cooling the plates with the lid ajar for an hour or two in the clean hood.