First dissolve EDTA in distilled water by adjusting the pH to 7.0 - 8.0
using a 2 M solution of NaOH; then add ferrous sulfate and the trace
element solution SL-6.
Trace element solution SL-6
Na2MoO4 x 2 H2O
NiCl2 x 6 H2O
CuCl2 x 2 H2 O
CoCl2 x 6 H2O
MnCl2 x 4 H2O
ZnSO4 x 7 H2O
Solutions A, B and D are sterilized separately by autoclaving at 121°C for
15 min under nitrogen atmosphere. Solution C is sterilized by filtration
or by autoclaving on a tightly closed vessel under an atmosphere of 80% N2
and 20% CO2 gas atmosphere. After sterilization combine the
four solutions and distribute as required under nitrogen atmosphere. for
solid medium add 15 g agar to solution A.