Formulation of the seahorse medium – high potassium (SM-140K⁺)

Reagent	Final concentration	Amount
CaCl2 2H2O	1.8 mM	9 mL of 0.1 M
FeCl2	0.000248 mM	12.8 μL of 0.01 M
KCl	115.36 mM	57.68 mL of 1.0 M
KHCO3	44.0 mM	22 mL of 1.0 M
KH2PO4	0.908 mM	4.54 mL of 0.1 M
MgSO4	0.814 mM	4.07 mL of 0.1 M
Phenol Red	0.0005%	500 μL of Stock
MEM Amino Acids	1×	10 mL of 50×
MEM Vitamins	1×	5 mL of 100×
ddH2O	n/a	387.45 mL
Total	n/a	500 mL

After sterile filtration of the freshly prepared SM-140K⁺ medium, it can be stored for up to 2 months in the dark at 4°C.