Yeast Transformation/Two-Hybrid System

[Chris Trotta]

I am currently trying to get a high efficiency transformation of yeast
with two plasmids.  I have only been able to get as high as 1x10^3
transformants/ug DNA.  This is not high enough to screen a library.

The second part of my post is to get general ideas on the two-hybrid
system.  Stuff like which strains have worked best, methods of 
screening, what hasn't worked etc.  I have begun screening the 
libraries in a His reporter strain YPB2 and have not had any success.
I also used a LexA derived system without any success either.  It 
seems as though there are quite a few false positives in each. In general 
I have recovered 40-50 positive clones which by themselves can activate
transcription.  I am interested in hearing about other screens.

C. Trotta
trotta at caltech.cco.edu