N/20 Medium

UTEX sells N/20 Medium at 1X concentration only. Stock solutions and individual components for this specific medium are currently not available for purchase.

N/20 Medium

Freshwater Medium

Micronutrients NO3 Thiamine Vitamin B12

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$ 55.00

N/20 Medium

Directions

For 1 L Total

To approximately 850 mL of dH₂O, add each of the components in the order specified (except vitamins) while stirring continuously.
Bring total volume to 1 L with dH₂O.
Cover and autoclave medium.
When cooled, add vitamins.
Store at refrigerator temperature.

#	Component	Amount	Stock Solution Concentration	Final Concentration
1	KH₂PO₄ (Sigma P 0662)	2 mL/L	17.5 g/200 mL dH2O	1.29 mM
2	NaNO₃ (Fisher BP360-500)	100 µL/L	25 g/200 mL dH2O	0.14 mM
3	K₂HPO₄ (Sigma P 3786)	1 mL/L	15 g/200 mL dH2O	0.43 mM
4	NaCl (Fisher S271-500)	1 mL/L	5 g/200 mL dH2O	0.43 mM
5	CaCl₂•2H₂O (Sigma C-3881)	1 mL/L	5 g/200 mL dH2O	0.17 mM
6	MgSO₄•7H₂O (Sigma 230391)	1 mL/L	15 g/200 mL dH2O	0.3 mM
7	P-IV Metal Solution	6 mL/L
8	Sodium acetate (Fisher BP 333)	0.67 g/L		8.12 mM
9	TES buffer (Sigma T 1375)	0.92 g/L		4.01 mM
10	Vitamin B₁₂	1 mL/L
11	Thiamine Vitamin Solution	1 mL/L

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N/20 Medium Recipe PDF

Safety Data Sheet (SDS)

FAQs:Algal Culture Media

Important Notes To Consider:

The quality of water, including natural seawater, is important. The term 'dH₂O' generally refers to distilled, deionized, distilled/deionized water, Milli-Q water (Millipore Corp.), etc. Natural seawater and natural freshwater should be obtained from a non-polluted source.
When dissolving chemicals, wait for the first component to dissolve before adding the second. Stirring, and sometimes the addition of heat, is often required to dissolve the chemicals efficiently. Preparation of stock solutions for frequently made algal culture media make preparing media convenient but also necessary to avoid errors from weighing very tiny amounts.
Attention should be given to the pH of the final medium. In most cases, if pH adjustment is required, this occurs before sterilization. Please note that autoclaving removes carbon dioxide from media lacking carbonate stabilizing buffers. This would make the medium very alkaline soon after removal from the autoclave. In these cases, you should wait approximately 24 hours for gaseous equilibrium before inoculating the medium.