# 88b: V24N MEDIUM


## Main sol. 88b

1. Prepare medium , then add (per litre): 

1.3	g	(NH4)2SO4	
0.28	g	KH2PO4	
0.25	g	MgSO4 x 7 H2O	
0.07	g	CaCl2 x 2 H2O	
0.02	g	FeCl3 x 6 H2O	
10	ml	**Allen's trace element solution**	
1000	ml	Distilled water	
1	g	Sulfur (powdered), powdered	
0.2	g	Yeast extract	
2	g	Starch (soluble), soluble	
0.4	mg	Resazurin	
0.5	g	Na2S x 9 H2O	

2. Adjust the pH to 6.0 with H2SO4 (25% v/v). Prepare the medium under 100% N2 gas phase and distribute anaerobically into rubber stoppered tubes or bottles (presterilized by autoclaving). The medium is sterilized by heating 2 hours at 85 °C on each of two following days.


## Allen's trace element solution

180	mg	MnCl2 x 4 H2O	
450	mg	Na2B4O7 x 10 H2O	
22	mg	ZnSO4 x 7 H2O	
5	mg	CuCl2 x 2 H2O	
3	mg	Na2MoO4 x 2 H2O	
3	mg	VOSO4 x 2 H2O	
1	mg	CoSO4 x 7 H2O	
1000	ml	Distilled water	

1. Adjust pH of final solution to 2 with 1 N HCl.