EX 11. | Isolation of Bacteria by Dilution Techniques (Streak Plate Only)

Mixed Culture

A culture that contains a variety of microorganisms growing together in a shared environment

Pure Culture

Contains a single kind of microbe

• The advantage of this is that it can be used to study characteristics such as growth, pathogenicity, metabolism, antibiotic susceptibility, etc since you’re focusing only on one species

Contamination

Presence of unwanted microorganisms

Streak Plate Technique

• Dilution method

• A loop is used to streak the mixed sample many times over the surface of a solid culture medium in a petri plate

• Used for isolating bacteria, and forming colonies (which are good for observation)

• Most common isolation technique