# C11: ASW:SES


## Mail sol. C11

750	ml	**ASW (Artificial Seawater)**	
250	ml	**SES (Soil Extract with Added Salts)**	

1. 3:1 mixture
2. See separate recipes ASW and SES.  This medium is made up in 2 parts which are 
mixed before autoclaving.


## ASW (Artificial Seawater)

0.5	g	Tricine	
3.75	ml	**Extra salts**	
2.5	ml	**Vitamin solution** (may be stored frozen at ­-20°C)	
25	ml	**SE1 (Soil Extract 1)**	
1000	ml	Natural sea water (filtered)	

1. Make up to 1 litre with filtered natural sea water.  Adjust the pH to 7.6 – 7.8 with
1N NaOH or 1N HCl. Autoclave at 15 psi.
2. Alternatively use "Ultramarine Synthetica" sea salts 33.6 g and make up to 1 
litre  with distilled water.  Adjust pH as above


## Extra salts

30	g	NaNO3	
1.2	g	Na2HPO4	
1	g	K2HPO4	


## Vitamin solution

0.0002	g	Biotin	
0.02	g	Calcium pantothenate	
0.004	g	Cyanocobalamine	
0.0004	g	Folic acid	
1	g	Inositol	
0.02	g	Nicotinic acid	
0.1	g	Thiamine HCl	
0.6	g	Thymine	


## SES (Soil Extract with Added Salts)

20	ml	K2HPO4 (1.0 g/l stock solution)	
20	ml	MgSO4 x 7 H2O (1.0 g/l stock solution)	
20	ml	KNO3 (10.0 g/l stock solution)	
100	ml	**SE1 (Soil Extract 1)**	
840	ml	Deionized water	

1. Make up to 1 litre with deionized water and autoclave at 15 psi for 15 minutes.


## SE1 (Soil Extract 1)

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 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.