10L Bristol Media Upgrade Kit: Bold 3N Medium

10L Bristol-to-Bold 3N Media Upgrade Kit

This upgrade kit includes all the necessary chemical and organic components needed to convert the 10L Bristol Media Kit into 10L of Bold 3N Medium. Bold 3N contains three times (3X) the amount of nitrogen as compared to Bristol, and includes the addition of a soilwater extract component, and vitamin B12.

Medium At A Glance

Water Type Freshwater
pH of Medium 6<pH<8
Contains NO3, Micronutrients, Vitamin B12

Looking for Bold 3N Medium in 1-Liter and test tube volumes?

View/purchase prepared and sterile 1X Bold 3N Medium


To upgrade the 10L Bristol Media Kit to Bolds 3N Media:

  1. Obtain and wear the appropriate PPE.
  2. Prepare the Bristol Media from the 10L Media Kit as directed, except the final volume should be brought up to 9L (9,000 mL) only instead of 10L.
  3. Carefully add the solutions (components #1-3) in order from the Media Upgrade Kit to the 9L of Bristol Media.
  4. Bring the volume up to 10 Liters with d-H2O and mix well.
  5. If needed, autoclave or filter-sterilize the medium and allow to cool to room temperature.
  6. Store at refrigerator temperatures.
Components In Upgrade Kit Final Concentration
NaNO3 8.82 mM
P-IV Metal Solution View Recipe
Soilwater: GR+ Medium View Recipe
Vitamin B12 View Recipe

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.