SunTag: A Protein-Tagging System for Signal Amplification in Gene Expression and Fluorescence Imaging

Tech ID: 24187 / UC Case 2014-155-0

Invention Novelty

This research tool consists of a two-vector system that can recruit an amplified biological signal to intra-cellular targets of interest.

Value Proposition

Most existing methods to amplify gene expression involve expressing a gene from a non-native promoter. The CRISPR system has been used to amplify gene expression from a native promoter by fusing a transcriptional activator to the deactivated Cas9 protein, which is then recruited to a gene of choice via a small guide RNA. However, existing CRISPR methods do not induce detectable activation of expression for most genes. This novel method amplifies CRISPR-mediated gene activation by over an order of magnitude.

The fluorescence of GFP fusion proteins often is not sufficiently bright or stable to enable live microscopy and visualization at the level of individual proteins. This invention can be used to enhance the intensity and duration of fluorophore labels to allow for live visualization of individual proteins.

Technology Description

The inventors have developed a two vector system for targeted signal amplification. One vector expresses the target of interest. The second vector contains a biological signal molecule (i.e. transcriptional activator or fluorescent protein). Co-expression of both vectors results in amplified signal at the cellular target of choice.


-       Research tool
Enhanced CRISPR-mediated gene activation
Imaging of intracellular molecules via an enhanced fluorescent signal

Looking for Partners

This fully-enabled technology is available for commercial license.

Stage of Development

Fully developed research tool

Data Availability

Under NDA/CDA 


Patent Status

Patent Pending

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  • Gilbert, Luke A.
  • Qi, Lei
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Other Information


vector, CRISPR, Cas9, fluorescence

Categorized As