# 104b: PY + X MEDIUM


## Main sol. 104b

5	g	Trypticase peptone (BD BBL)	
5	g	Meat peptone (pepsin-digested)	
10	g	Yeast extract	
40	ml	**Salt solution**	
0.5	ml	Sodium resazurin (0.1% w/v)	
0.5	g	L-Cysteine HCl x H2O	
5	g	D-Glucose	
960	ml	Distilled water	

1. Dissolve ingredients (except cysteine and glucose) and sparge medium with 100% N2 gas for 30 - 45 min to make it anoxic. Add cysteine and adjust pH to 7.0, then dispense medium under 100% N2 gas atmosphere into anoxic Hungate-type tubes or serum vials and autoclave. After autoclaving add glucose or any other substrate from sterile anoxic stock solutions prepared under 100% N2 gas atmosphere. Adjust pH of complete medium to 6.8 - 7.0, if necessary.


## 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