From ActinoBase

International Streptomyces Project-3 Medium (ISP-3)

International Streptomyces Project Medium 3 (ISP-3) is a rich general use media. Alternatively called oatmeal agar.


  • 20 g White Oats
  • 18 g Agar
  • 1 mL Trace salts solution
    • 0.1 g FeSO4 x 7H2O
    • 0.1 g MnCl2 x 4H2O
    • 0.1 g ZnSO4 x 7H2O
    • 100 mL dH2O
  • 1 L dH2O


  1. Boil 20 g oats in 1L dH2O for 20 mins
  2. Filter oats through cheesecloth and top volume up to 1L
  3. Adjust pH to 7.2, add agar, and autoclave
  4. Add 1 mL Trace Salts solution


  • Inducing sporulation of environmental isolates
  • Screening for antibiotic production


When screening for antibiotic production, there can be significant differences between media prepared in-house and bought in media