# 629: STALEY'S MAINTENANCE MEDIUM


## Main sol. 629

5	g	Peptone	
0.5	g	Yeast extract	
20	ml	**Hutner's salts**	
10	ml	**Vitamin solution** (filter-sterilized)	
970	ml	Distilled water	
15	g/l	Agar, for solid medium	

1. Dissolve peptone and yeast extract in the distilled water, adjust the pH to 7.2 and sterilize. After the medium has cooled add the Hutner's salts and Vitamin solution.
2. For solid medium use 15.0 g agar.


## Hutner's salts

10	g	Nitrilotriacetic acid (NTA)	
29.7	g	MgSO4 x 7 H2O	
3.335	g	CaCl2 x 2 H2O	
9.25	mg	(NH4)6Mo7O24 x 4 H2O	
99	mg	FeSO4 x 7 H2O	
50	ml	**"Metals 44"**	
950	ml	Distilled water	

1. Dissolve the nitrilotriacetic acid.
2. Adjust pH to 7.0 with KOH (~7.3 g).
3. Dissolve other salts separately and combine.
4. Adjust pH to 6.8 with NaOH or H2SO4.


## Vitamin solution

0.1	mg	Vitamin B12	
2	mg	Biotin	
5	mg	Thiamine-HCl x 2 H2O	
5	mg	Calcium pantothenate	
2	mg	Folic acid	
5	mg	Riboflavin	
9	mg	Nicotinamide	
1000	ml	Distilled water	

1. Filter-sterilized. 


## "Metals 44"

250	mg	Na-EDTA	
1095	mg	ZnSO4 x 7 H2O	
500	mg	FeSO4 x 7 H2O	
154	mg	MnSO4 x H2O	
39.2	mg	CuSO4 x 5 H2O	
24.8	mg	Co(NO3)2 x 6 H2O	
17.7	mg	Na2B4O7 x 10 H2O	
1000	ml	Distilled water	

1. Dissolve the EDTA and add a few drops of concentrated H2SO4 to retard precipitation of the heavy metal ions.