The Protein Interactions Expert

ULTImate Y1H

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ULTImate Y1H (yeast one-hybrid) uses a DNA sequence as a bait.

Derived from our ULTImate Y2H™ technology, it allows to screen to saturation highly complex libraries to find the protein partners of a DNA bait.

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  • Identify and characterize DNA-protein interactions

Molecules Tested

  • DNA sequences (e.g. promoter regions, responsive elements)

How does it work?

To conduct an ULTImate Y1H assay, a DNA sequence of interest, the ‘DNA bait’, is first cloned upstream of a reporter gene to create a ‘DNA bait - reporter’ construct.
The DNA bait attached to the reporter is cloned into a centromeric vector or integrated into the genome of a dedicated yeast strain by site-specific recombination. A cell-to-cell mating is then performed between the ‘DNA bait - reporter’ yeast strain and a yeast strain pre-transformed with a high complexity domain library. This allows screening for novel protein partners of this DNA bait in an exhaustive fashion.

For more details about our screening technology and libraries, please refer to our ULTImate Y2H and ULTImate Libraries pages.


  • Fast and exhaustive screening thanks to Hybrigenics patented cell-to-cell mating protocol
  • Detection of even weak interactions and interactions with proteins whose transcripts are rare
  • Full sophisticated bioinformatics analysis of the results including confidence scores
  • Up to 380 positive clones analyzed (5’ and 3’ sequences)
  • Scientific assistance for the best outcome of your project


The results of your ULTImate Y1H screen come fully analyzed to help you focus on the most relevant interactions. The deliverables include the list of identified protein partners, the experimental interaction domain on each protein and a confidence score. Please click here for a detailed presentation.

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