Day 1: Plating the Mixed Population

1. Find microsatellite-containing strains in the -80°C freezer. They will be labeled with the appropriate microsatellite sequence located in the rhamnose operon (eg. "(CA)₁₂"). See below for the list of microsatellites.
2. Using careful sterile technique, dilute 1:1000 in saline by adding 10μl frozen stock in 10ml saline.
3. Dilute this again 1:10 by adding 1ml of the first dilution in 9ml saline.
4. Plate 100μl on minimal glucose (MG) plates. Label plates with strain and date.
5. Let grow overnight at 37°C.

Day 2: Picking Colonies

We'll start off picking 24 colonies. These will end up being our 24 replicates that are passaged simultaneously day-to-day.

1. Get out a sterile 384 well freezer plate. Label with strain and date. In the top row, add 50μl 80% glycerol. Sterility is very important here.
2. Choose the 24 colonies closest to the written date on the plate that are far enough away from other colonies to be picked without contamination.
3. Using a sterilized, rounded pasteur pipet, pick each of the 24 colonies and spin it in a glycerol well.
4. With a sterile loop touch the remainder of the colony on the plate and streak onto a new MG plate, in a circular fashion, diluting as you go around.
5. Let grow overnight at 37°C.

Day 3: Passaging Colonies

1. Pick the last single colony and passage onto a new MG plate.

Freeze Clones

-- Main.LindseyWolf - 18 May 2011