# C106: Waris-H ## Mail sol. C106 1 ml Ca(NO3)2 x 4 H2O (100 g/l stock solution) 1 ml MgSO4 x 7 H2O (20 g/l stock solution) 1 ml (NH4)2HPO4 (20 g/l stock solution) 1 ml KNO3 (100 g/l stock solution) 1 ml HEPES (238.31 g/l stock solution) 1 ml **Fe-EDTA** 1 ml **P-II Metals** 1 ml **Vitamin mix** 10 ml **SE2 (Soil Extract 2)** 1000 ml Deionized water 1. Make up to 1 litre with deionized water and adjust pH to 7.0 with 1M NaOH or 1M HCl. Autoclave at 15 psi for 15 minutes. ## Fe-EDTA 5.22 g Na2-EDTA x 2 H2O 4.98 g FeSO4 x 7 H2O 54 ml KOH (1 N) 1. 1M KOH is heated for 30 min (100°C); once cooled it is added to the mixture. Then heat the solution for 20 mins at 115°C ## P-II Metals 3 g Na-EDTA x 2 H2O 1.14 g H3BO3 0.021 g ZnSO4 x 7 H2O 0.004 g CoCl2 x 6 H2O 0.144 g MnCl2 x 4 H2O 1000 ml Distilled water 1. Dissolve EDTA and boric acid in distilled H2O, then add metals one after the other. ## Vitamin mix 0.1 g Thiamine HCl 1 mg Biotin 0.2 mg Cyanocobalamin 0.1 mg Niacinamide ## SE2 (Soil Extract 2) x Soil (air-dried) x Distilled water 1. Site selection for a good soil is very important and for most purposes a soil from undisturbed deciduous woodland is best. Sites to avoid are those showing obvious signs of man's activity and particular care should be taken to avoid areas where fertilizers, crop sprays or other toxic chemicals may have been used. 2. A rich loam with good crumb structure should be sought. Stones, roots and larger invertebrates should be removed during an initial sieving through a 1 cm mesh. The sieved soil should be spread to air dry and handpicked for smaller invertebrates and roots. It should be turned periodically and picked over again. When dry sieve through a finer mesh (2-4 mm) and store in an airtight container away from light and heat. 3. Soil is prepared as above. Air-dried soil and twice its volume of supernatant distilled water are autoclaved together at 15 psi for 2 hours and left to cool. The supernatant is then decanted and then distributed to containers in volumes suitable for making up batches of media. The aliquots and their containers are autoclaved for an appropriate length of time (e.g. 1 litre or less for 15 minutes) and are then kept in a cool place (e.g. a refrigerator) until required.