Talk to a Flinn Scientist or Customer Service Rep1-800-452-1261M-F 7:30am-5pm CT

Teacher Resources

How do I prepare culture media for algae?


Bristol's Modified Medium

Make six stock solutions, each with one of the following salts dissolved in 400 milliliters of water:

  • 10 g sodium nitrate (NaNO3)
  • 1 g calcium chloride (CaCl2 •2H2O)
  • 3 g magnesium sulfate (MgSO4 7H2O)
  • 3 g potassium phosphate dibasic (K2HPO4)
  • 7 g potassium phosphate monobasic (KH2PO4)
  • 1 g sodium chloride (NaCl)

Take 10 mL of each stock solution and add to 900 mL of distilled water. Next add one drop of 1% ferric chloride solution, 40 mL of Pringsheim's soil-water extract and autoclave.

Pringsheim's Soil Water

Select a rich garden soil which has not been recently fertilized. Add 300 g of the soil to a gallon jar. Fill three-fourths full with distilled water then add one gram of calcium carbonate (CaCO3). Plug or cap jar loosely and steam for one hour per day on each of three consecutive days.

To culture Spirogyra, do not add calcium carbonate. To culture Euglena add one-fourth of a pea cotyledon before steaming. This will enhance growth. To culture diatoms, add 10-30 mg of sodium metasilicate (Na2SiO3 9H2O) to every liter of medium.

P.O. Box 219, Batavia, IL60510



*Advanced Placement and AP are registered trademarks of the College Board, which was not involved in the production of, and does not endorse, these products.