Yeast 2-Hybrid Screening

[Martin Cann]

I'm working on the yeast 2-hybrid system and have some questions.  After
triple selection (-Leu/-Trp/-His), I have hundreds of colonies (>300). 
I am currently doing a blue/white screen.  Does anyone have any
suggestions for cutting down the number of colonies.  I do not think
that these are all "ture" poitives and would like to cut down the number
significantly before I start to purify DNA and sequence it.  

Barbara