Colony Screen
Dominik Haudenschild, March 26, 1997

1 Cool plates for 1 hour at 4°C before doing colony lifts
2 Carefully put dry membrane onto agar plate, but DO NOT adjust position once it has touched the plate
3 Allow membrane to wet for 2-3 minutes
4 Meanwhile, mark membrane position for subsequent re-alignment using a needle
5 Pipet 3-4ml of 0.5N NaOH onto Saran Wrap
6 Place membrane colony side up onto pool of NaOH for 2 minutes
7 Repeat steps 5-6 with fresh 0.5N NaOH for another two minutes
8 Pipet 3-4ml of 1M Tris pH 7.5 onto plastic wrap
9 Place membrane colony side up onto pool of Tris for 2 minutes
10 Repeat steps 8-9 with fresh Tris for another two minutes
11 Place membrane colony side up onto 3MM paper and UV crosslink with Stratalinker set to «AutoCrosslink»
12 Return plates to 37°C incubator for 1-2 hours, just so that the original colonies start to become visible again, but not
so long that the satellite colonies become too large

Membranes can now be stored dry until ready to be probed