Isolating Actinobacteria from soil environments

Equipment & Materials

• Sterile containers to transport the soil
• A heat block
• Plates of Isolation media
• A vortexer
• ¼ Strength Ringer’s Solution
• Nalidixic acid, cycloheximide, and nystatin

Preparation of Soil

1. Incubate 1g of soil at 50oC for 1 hour in order to kill vegetative organisms
2. Suspend the soil in 10 mL ¼ Strength Ringer’s and vortex for 10 mins in order to thoroughly suspend your sample
3. Dilute your soil suspension 1/10 and 1/100 and spread 200 µL of these onto plates of your isolation media supplemented with 25 µg mL-1 nystatin, 25 µg mL-1 cycloheximide, and 10 µg ml-1 nalidixic acid
4. Incubate your plates at 30oC for three weeks, the temperature and duration will vary depending on what you are aiming to isolate
5. Select actinobacterial colonies that have grown and patch them onto the same agar in order to isolate the strains