liquid Bgal assay

[dave eide]

Hi Kathy,

Tropix sells a luminescent B-gal substrate called Galacto-Light.  I've 
not used it but their literature claims that it is 1000-10000x more 
sensitive than ONPG.  Sounds like it might be of use to you.  Tropix is 
at 1-800-542-2369.

Dave Eide

P.S.  Check also BioTechniques 14: 762 (1993)

Hello Kathy,

I also have been wondering how to do liquid beta-gal assays on low activity
hybrids, and I was about to post a request on the yeast Net when I saw your
posting.  I have some interactions in my lab that are barely detectable; some
days they are there and some days not.  One suggestion that was made to me 
was to get a reporter strain with multiple tandem copies of the Gal4 binding
site (a specific 17-mer) upstream of the lacZ reporter gene.  The standard
two-
hybrid strains (HF7c from Clontech and Y153 form Elledge's lab) have just one
copy of the binding site.   Increasing the number to 4 increases the chances
that the hybrid will bind to the promotor and activate the reporter.

***(I thought Y153 had 4 binding sites)***

I do not know anybody who has such a strain, but I suspect that it is out 
there.  I was going to post a request for such a strain, but I think I will
wait to see what your posting brings up.  If such a strain is found, or if
some other solution to the problem of weak interactions is offered, could you
please EMail me directly? as well, you should post a summary to BioNet to
satisfy Francis.