Iron Chelate Solution – Plant Tissue Culture Protocol

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

1. Dissolve 0.278 g of ferrous sulfate heptahydrate (Product No. F8263) in 350 ml of tissue culture grade water (Product No. W3500). Heating may be required.
2. Dissolve 0.3725 g of disodium EDTA (Product No. E6635) 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. E6635) 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. F8263). 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).