Allen Medium



Allen Medium Recipe

Modification of M.M. Allen's freshwater medium for blue-greens. Suitable for axenic and xenic cultures. The marine LB 1928 Spirulina platensis [Medium: ES-enriched seawater] can be adapted to Allen medium (D. James 1982, pers. Comm.).

Directions

For 1 L Total

  1. To approximately 950 mL of dH2O, add each of the components in the order specified (except vitamins) while stirring continuously.
  2. Adjust pH to 7.8
  3. Bring the total volume to 1 L with dH2O.
    • *For 1.5% (w/v) agar medium, add 15 g of agar into the flaskl; do not mix.
  4. Cover and autoclave medium.
  5. Store at refrigerator temperature.

# Component Amount Stock Solution Concentration Final Concentration
1 HEPES buffer (Sigma H-3375) 2.3 g/L   0.01 M
2 NaNO3 (Fisher BP360-500) 1.5 g/L   0.018 M
3 P-IV Metal Solution 1 mL/L    
4 K2HPO4 (Sigma P 3786) 5 mL/L 1.5 g/200 mL dH2O 0.215 mM
5 MgSO4·7H2O (Sigma 230391) 5 mL/L 1.5 g/200 mL dH2O 0.152 mM
6 Na2CO3 (Baker 3604) 5 mL/L 0.8 g/200 mL dH2O 0.19 mM
7 CaCl2·2H2O (Sigma C-3881) 10 mL/L 0.5 g/200 mL dH2O 0.17 mM
8 Na2SiO3·9H2O (Sigma 307815) 10 mL/L 1.16 g/200 mL dH2O 0.204 mM
9 Citric Acid·H2O (Fisher A 104) 1 mL/L 1.2 g/200 mL dH2O 0.029 mM