Detecting GFP colonies

[tim stearns]

We have isolated brighter GFP mutants by screening yeast colonies under 
a fluorescence microscope.  For this to be efficient, you want the 
lowest magnification possible.  The easiest way to achieve this is to 
remove the objective and eyepieces from your microscope, and to look 
down the tube at your colonies, using the filter set of choice (a 
fluorescein set is fine).  We tried it with handheld UV lamps and could 
never get high enough signal/noise.

Tim Stearns
stearns at leland.stanford.edu