Iron Chelate Solution

 To prepare 1L of a 10 X iron chelate solution:

1. Dissolve 0.278 g of ferrous sulfate heptahydrate (Product No. F 8263) in 350 ml of tissue culture grade water (Product No. W 3500). Heating may be required.
2. Dissolve 0.337 g of disodium EDTA (Product No. E 6635) in 350 ml using tissue culture grade water. Heating may be required.
3. When both components are dissolved, combine the solutions and bring up to the final volume of 1 L using tissue culture grade water. This will yield a clear yellow solution. (Concentrations of components are based upon those present in MS basal salt formulations and utilized in McCown's Woody Plant Medium).

ALTERNATE METHOD

To prepare 1L of a 200 X iron chelate stock solution:

1. Dissolve 7.45 g of disodium EDTA (Product No. E 6635) in 900 ml of tissue culture grade water. A clear solution is obtained in 20 minutes at room temperature (25-27 °C).
2. Gradually add 5.52 g of ferrous sulfate heptahydrate (Product No. F 8263). A clear yellow solution is obtained immediately.
3. Store the iron chelate stock solution in an amber bottle to protect it from exposure to light.
4. Use 5 ml of the 200 X iron chelate stock solution to prepare 1 L of culture medium requiring 27.8 mg/L of ferrous sulfate and 37.25 mg/L of disodium salt of EDTA (e.g., Murashige and Skoog, 1962; Gamborg, et al., 1968; Lloyd and McCown, 1981).