Jenna M. Lang edited Isolation.md  about 9 years ago

Commit id: 8a4ed23087a0e7cfde11e711ac18cc97f920adeb

deletions | additions      

       

Gently (so as not to break the agar surface) rub, _i.e._, "streak" the swab across the entire surface of an agar plate. Be sure to rotate the swab as you are doing so to ensure that all sides of the swab make contact with the plate. Incubate the plate at the desired temperature (in our case, usually 37°C or room temperature) until colonies appear.  ##Dilution Streak (streaking for individual colonies) x2  After incubation, choose desired colonies (we typically attempt to maximize the diversity of colony morphologies) and dilution streak them onto individual plates. Dilution streaking involvesa  spreading out a chosen colony such that new  single colonies grow on a new plate (details can be found online). After growth to visible colonies, repeat the dilution streaking to help ensure purity of the culture. Some organisms will only grow in tight association with others, and a mixed culture will prove difficult to classify(because there will be more than one 16S rDNA sequence amplified and sequenced)  anddifficult to  assemble. ##Liquid Culture  After the second dilution streaking, a liquid culture is needed both for long-term storage and for DNA extraction. Transfer a single colony from each dilution streak plate into 5 mls of culture media and grow for 1-3 days until cloudy. Once the liquid culture is ready, prepare a 10% final concentration glycerol stock for long-term storage at -80°C from 1-2 ml of the sample.