# 104: PYG MEDIUM (modified)


## Main sol. 104

5	g	Trypticase peptone	
5	g	Peptone	
10	g	Yeast extract	
5	g	Beef extract	
5	g	Glucose	
2	g	K2HPO4	
1	ml	Tween 80	
40	ml	**Salt solution**	
1	mg	Resazurin	
0.2	ml	**Vitamin K1 solution**	
10	ml	**Haemin solution**	
0.5	g	L-Cysteine HCl x H2O	
950	ml	Distilled water	

1. The vitamin K1, haemin solution and the cysteine are added after the medium has been boiled and cooled under CO2. Adjust pH to 7.2 using 8 N NaOH. Distribute under N2 and autoclave.


## Salt solution

0.25	g	CaCl2 x 2 H2O	
0.5	g	MgSO4 x 7 H2O	
1	g	K2HPO4	
1	g	KH2PO4	
10	g	NaHCO3	
2	g	NaCl	
1000	ml	Distilled water	


## Haemin solution

50	mg	Haemin	
1	ml	NaOH (1 N)	
100	ml	Distilled water	

1. Dissolve 50 mg haemin in 1 ml 1 N NaOH; make up to 100 ml with distilled water and filter sterilize. Store refrigerated.


## Vitamin K1 solution

0.1	ml	Vitamin K1	
20	ml	Ethanol (95 %)	

1. Dissolve 0.1 ml of vitamin K1 in 20 ml 95% ethanol and filter sterilize. Store refrigerated in a brown bottle.