ISP Medium 7 (Tyrosine Agar Medium Base) – For Streptomyces Cultivation & Identification

ISP Medium 7 (Tyrosine Agar Medium Base) is a dehydrated culture medium formulated for the cultivation and identification of Streptomyces species. It is part of the International Streptomyces Project (ISP) classification system and is widely used in microbial taxonomy and actinomycete studies.

This medium requires the addition of glycerol (15 g/L) before sterilization to support optimal growth.

• Form: Dehydrated powder medium

• Packaging: 250 g/bottle

• Storage: Room temperature

• Shelf Life: 3 years

✅ Product Formula (per liter)

• L-Tyrosine …………………………………… 0.5 g

• L-asparagine ………………………………… 1.0 g

• Di-potassium hydrogen phosphate (K₂HPO₄) ………… 1.0 g

• Magnesium sulphate (MgSO₄) …………………….. 0.5 g

• Sodium chloride (NaCl) ………………………… 0.5 g

• Ferrous sulphate (FeSO₄) ………………………. 1.1 mg

• Manganese chloride (MnCl₂) ……………………. 1.0 mg

• Zinc sulphate (ZnSO₄) ………………………… 1.0 mg

• Agar ………………………………………… 15.0 g

• Final pH: 7.2 ± 0.2 (at 25℃)

✅ Instructions for Use

1. Suspend 18.5 g of the medium base in 1 liter of deionized water or 30% natural seawater.

2. Add 15 g of glycerol and mix well.

3. Heat to boiling until fully dissolved.

4. Dispense into suitable containers.

5. Sterilize by autoclaving at 121℃ for 15 minutes.

6. After sterilization, shake well to prevent agar sedimentation and uneven solidification.