F/2 Media

f/2 Medium Stock Solutions:

Quantity per liter of Media	Compound	Stock Concentration
1.0 ml	NaNO3	75.0 g/L dH2O	Add to Media
1.0 ml	NaH2PO4.H2O	5.0 g/L dH2O	Autoclave separately
1.0 ml	Na2SiO3.9H2O	30.0 g/L dH2O	Autoclave separately
1.0 ml	f/2 Trace Metal Solution	(see recipe below)	Autoclave separately
0.5 ml	f/2 Vitamin Solution	(see recipe below)	Add to Media

Add Nitrate and vitamin solution directly to seawater and autoclave. Autoclave separately aliquots of the phosphate, trace metals and silicate. Add these aseptically to your media once it has cooled to room temperature. Note: f/2 Medium contains extensive silica precipitate and should be used only when growing diatoms. For other algal groups use f/2-Si Medium (see below). Store non-sterile stocks in the REVCO refrigerator.

Trace Metal Solution

To 950 mL distilled H2O add:

Quantity	Compound	Stock Solution
1.3 g	FeCl3.6H2O	-
8.7 g	Na2EDTA.2H2O	-
1.0 ml	CuSO4.5H2O	980 mg / 100 ml dH20
1.0 ml	Na2MoO4.2H2O	630 mg / 100 ml dH20
1.0 ml	ZnSO4.7H2O	2.2 g / 100 ml dH20
1.0 ml	CoCl2.6H2O	1.0 g / 100 ml dH20
1.0 ml	MnCl2.4H2O	18.0 g 100 ml dH20

Solution will initially be cloudy. Add 1N NaOH to adjust pH to about 4.5; solution should clear unless too much NaOH has been added. Bring final volume to one liter.

Vitamin Solution

To 950 mL dH2O add:

Quantity	Compound	1^o Stock Solution	Tip
1.0 ml	Vitamin B12	10 mg / 10 ml dH2O
1.0 ml	Biotin	10 mg / 10 ml dH2O	Dissolve in a little 0.1N NaOH first
200.0 mg	Thiamine HCl	-

Make final volume up to 1.0 L with dH₂O. Store primary stock solutions in freezer. Store completed vitamin solution in the refrigerator or freeze small aliquots.

References

Guillard R.R.L. and Ryther J.H. (1962) Studies of marine planktonic diatoms. I. Cyclotella nana Hustedt and Detonula confervacea Cleve. Can. J. Microbiol. 8: 229-239.

Guillard R.R.L. (1975) Culture of phytoplankton for feeding marine invertebrates. in "Culture of Marine Invertebrate Animals." (eds: Smith W.L. and Chanley M.H.) Plenum Press, New York, USA. pp 26-60.

f/2 Derivatives

f/2-Si:
Prepare as for f/2 Medium but omit Na2SiO3.9H2O.

f/50-Si:

Dilute completed f/2 – Si media 25-fold with sterile seawater