Name: E27
Creator: MediaDive
License: http://creativecommons.org/licenses/by/4.0/

ml

	Compound	Amount	Unit
	Part 1	500	ml
	Natural sea water (filtered and autoclaved)	500	ml
1 This medium is made up in 2 parts which are autoclaved separately at 15 psi and mixed aseptically (1:1), when cool. This avoids precipitation.
2 Alternatively, use 17.5g of “Ultramarine Synthetica” sea salts in 500ml of distilled water.

Part 1 #

500

	Compound	Amount	Unit
	SE1 (Soil Extract 1)	25.000	ml
	KNO₃	0.050	g
	K₂HPO₄	0.005	g
	MgSO₄ x 7 H₂O	0.005	g
	Glucose	0.250	g
	Tryptone (Oxoid L42)	0.025	g
	Liver digest (Oxoid L27)	0.025	g
	Cyanocobalamine	0.100	μg
	Thiamine HCl	50.000	μg
	Distilled water	500.000	ml
1 Distilled water to 500 ml. Autoclave

SE1 (Soil Extract 1) #

1000

	Compound	Amount
	Soil (air-dried)	trace
	Distilled water	trace
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 filtered through Whatman No 1 filter paper, 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.