background in 2 hybrid system

[bbraun at ucla.edu]

Ingrid,

You do not mention this, but does is this strain truly dependent on His
without the bait plasmid?  I have not done a two hybrid screen, but
I would hesitate to proceed without two independent tests of interaction.
Also, the His selection allows you to plate a large number of transformants
and still get a reasonable number of viable colonies.

My $0.02,
Benjamin

In <46dotj$ptl at mule.fhcrc.org>, Ingrid Wolf <iwolf at fhcrc.org> writes:
>I have cloned a plasmid encoding a LexA-fusion protein which I want to 
>use for the yeast two hybrid screen. This bait-plasmid alone or together 
>with the empty VP16 vector allows already growth of the transformed 
>yeast clones on plates lacking His but they stay white on X-gal 
>plates.With a positiv control, a known interacting protein fused to 
>VP16,  the yeast transformants grow on plates lacking His and turn to 
>dark blue on X-gal plates. The background growth of the bait on plates 
>lacking His can not be suppressed by 3-aminotriazole (I titrated all 
>concentrations up to 200 mM). My question is:
> Has anybody made a two hybrid screen by monitoring the interaction only 
>with the blue color?
>Please give me a message to:      iwolf at fhcrc.org
>Thank you.
>
>