UTEX only sells complete media at 1X concentration. Stock solutions and individual components are currently not available for purchase.


BG-11 Medium



View Media Receipe

View Available Downloads



BG-11 Medium

Improved recipe as of March 2009

Directions

For 1 L Total

Liquid media:
  1. To approximately 900 mL of dH2O add the first 9 components in the order specified while stirring continuously.
  2. Bring total volume to 1 L with dH2O.
  3. Cover and autoclave medium.
  4. Allow to cool then store at refrigerator temperature.
Agar media:
  1. To approximately 400 mL of dH2O add the first 9 components in the order specified while stirring continuously.
  2. Bring total volume to 500 mL with dH2O.
  3. In a separate container add 15 g of agar to 500 mL of dH2O.
  4. Cover and autoclave both solutions.
  5. In a water bath allow both solutions to cool to 45-50 °C.
  6. Add sterile Sodium Thiosulfate (Component 10) to agar solution and mix well.
  7. Combine both agar and liquid solutions, mix well. Note the agar can solidify quickly.
  8. Allow to cool then store at refrigerator temperature.

# Component Amount Stock Solution Concentration Final Concentration
1 NaNO3
(Fisher BP360-500)
10 mL/L 30 g/200 mL dH2O 17.6 mM
2 K2HPO4
(Sigma P 3786)
10 mL/L 0.8 g/200 mL dH2O 0.23 mM
3 MgSO47H2O
(Sigma 230391)
10 mL/L 1.5 g/200 mL dH2O 0.3 mM
4 CaCl22H2O
(Sigma C-3881)
10 mL/L 0.72 g/200 mL dH2O 0.24 mM
5 Citric Acid•H2O
(Fisher A 104)
10 mL/L 0.12 g/200 mL dH2O 0.031 mM
6 Ferric Ammonium Citrate 10 mL/L 0.12 g/200 mL dH2O 0.021 mM
7 Na2EDTA•2H2O
(Sigma ED255)
10 mL/L 0.02 g/200 mL dH2O 0.0027 mM
8 Na2CO3
(Baker 3604)
10 mL/L 0.4 g/200 mL dH2O 0.19 mM
9 BG-11 Trace Metals Solution 1 mL/L
10 Sodium Thiosulfate Pentahydrate (agar media only,sterile)
(Baker 3946)
1 mL/L 49.8 g/200 mL dH2O 1 mM

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.