Bristol Medium

NOW AVAILABLE

Bristol Medium is now available in larger volumes.

Bristol Medium

H.C. Bold's modification of Bristol's recipe (Bold 1949). General purpose freshwater medium and as bristol's solution, an essential component of other media--see Bold 1NV, Bold 3N, Bristol-NaCl, LDM, Proteose, Soil extract, and Trebouxia.

Directions

For 1 L Total

To approximately 900 mL of dH₂O add each of the components in the order specified while stirring continuously.
Bring total volume to 1 L with dH₂O.
- *For 1.5% agar medium add 15 g of agar into the flask; do not mix.
Cover and autoclave medium.
Store at refrigerator temperature.

#
1
Component	NaNO₃ (Fisher BP360-500)
Amount	10 mL/L
Stock Solution Concentration	10 g/400mL dH2O
Final Concentration	2.94 mM
2
Component	CaCl_2•2H₂O (Sigma C-3881)
Amount	10 mL/L
Stock Solution Concentration	1 g/400mL dH2O
Final Concentration	0.17 mM
3
Component	MgSO_4•7H₂O (Sigma 230391)
Amount	10 mL/L
Stock Solution Concentration	3 g/400mL dH2O
Final Concentration	0.3 mM
4
Component	K₂HPO₄ (Sigma P 3786)
Amount	10 mL/L
Stock Solution Concentration	3 g/400mL dH2O
Final Concentration	0.43 mM
5
Component	KH₂PO₄ (Sigma P 0662)
Amount	10 mL/L
Stock Solution Concentration	7 g/400mL dH2O
Final Concentration	1.29 mM
6
Component	NaCl (Fisher S271-500)
Amount	10 mL/L
Stock Solution Concentration	1 g/400mL dH2O
Final Concentration	0.43 mM

#	Component	Amount	Stock Solution Concentration	Final Concentration
1	NaNO₃ (Fisher BP360-500)	10 mL/L	10 g/400mL dH2O	2.94 mM
2	CaCl_2•2H₂O (Sigma C-3881)	10 mL/L	1 g/400mL dH2O	0.17 mM
3	MgSO_4•7H₂O (Sigma 230391)	10 mL/L	3 g/400mL dH2O	0.3 mM
4	K₂HPO₄ (Sigma P 3786)	10 mL/L	3 g/400mL dH2O	0.43 mM
5	KH₂PO₄ (Sigma P 0662)	10 mL/L	7 g/400mL dH2O	1.29 mM
6	NaCl (Fisher S271-500)	10 mL/L	1 g/400mL dH2O	0.43 mM

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Bristol 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.