One of the most impressive demonstrations of bioluminescence is also the easiest. Dinoflagellates, the most common sources of bioluminescence at the sea surface, are readily grown in the laboratory. They produce bright bioluminescence upon agitation. The following instructions describe how to obtain dinoflagellate cultures and grow them at home, school, or laboratory. Then check out the Web page on bioluminescence demonstrations. So good luck!

The book Algal Culturing Techniques is a comprehensive reference on the culturing of dinoflagellates and other phytoplankton.

Cultures

Here are some places to obtain luminescent dinoflagellates. Note that this list is not an endorsement, just a suggestion:

Nutrients

If you can grow houseplants then you can maintain dinoflagellates. Just as your houseplants need fertilizer to help them grow, so too do dinoflagellates have nutritional needs. Dinoflagellates require nitrate, phosphate, trace metals, and vitamins. These nutrients are prepared under sterile conditions, so if you don’t have an autoclave available, it is easier to buy already prepared media than to make your own.

  • Both Pyrofarms and Urbz (see above) sell ready to use nutrients for dinoflagellate growth.
  • Carolina Biological Supply Co. [800-547-1733 for western U.S. or 800-334-5551 for Eastern U.S.]
    • Alga-Gro seawater medium “for culturing marine algae”.
      This is a complete ready-to-go solution. Just add dinoflagellates.
    • A guide to culturing algae.
  • Sigma-Aldrich Co. [800-325-3010 for USA/Canada, 314-771-5750 outside USA/Canada (call collect)], www.sigmaaldrich.com 
    • Guillard’s (f/2) marine enrichment basal salt mixture without silicate
      “With the macro- and micronutrients as described by Guillard (1975).”
      Sigma #G1775, price $14.80 (USD) for 10 L.
      This is a complete ready-to-go solution. Just add dinoflagellates!
  • National Center for Marine Algae and Microbiota
    • Choose L1 or f/2 media for dinoflagellates.
    • Prepared media (1 gallon, ready to use) or media kits (just add seawater)
    • For the do-it-your-selfer (for the brave only, culture recipes that require a sensitive balance and autoclave for sterilization.

Maintaining Cultures

All you need are lights and a timer. If you use sterile media and glassware, your cultures will continue forever; every month pour about 1/4 of the culture into some new medium. If you can’t maintain sterile culture conditions, the cells could last only a few weeks to a month before bacteria overgrow the culture.

  • Room temperature (20-25 degC)
  • Illumination with cool-white fluorescent or LED bulbs. Shop lights work well.
  • Light cycle (12 hr each light, dark). Demonstrate bioluminescence at least 2 hours into the dark cycle.
  • Culture flasks — Sterilized glassware if autoclave is available, otherwise use disposable tissue culture flasks
  • Culture media (see above)

Measuring Cell Concentration

The amount of bioluminescence that is observed or measured depends on the number of cells present. The simplest way to determine cell concentration is to count a subsample of cells using a stereo microscope. Here is a protocol to count Pyrocystis fusiformis:

  • Gently swirl flask a few times to thoroughly mix contents.
  • Remove 200 µL sample using a P1000 pipetman or equivalent pipette that allows you to measure a known volume.
  • Place sample into well slide.
  • Count number of cells under stereo microscope.
  • Adjust volume so that there are 10-20 cells in the volume (i.e., they are easy to count).
  • Take 5-6 samples, placing each in a well of a depression slide.
  • Count # cells under stereo microscope. Calculate average cell count.
  • Calculate # cells/mL (average # cells / volume used * 1000 µL/mL)
  • For example, 20 cells / 200 µL * 1000 µL/mL = 100 cells/mL