Lead Inventor:
Jeanette Chloe Bulinski Ph.D.
Green Fluorescent Protein Marker Lacks Signal Consistency:
The discovery and development of GFP (Green Fluorescent Protein) as an effective marker for cellular components has been a great boom to biological research. Due to its ability to be fused to natural elements inside cells and its benign effect on living cells, the use of GFP allowed the visualization of sub-cellular structures in a living cell in real-time. In addition, GFP fusions integrated into the genome theoretically allows for the expression of proteins to be quantitatively measured by fluorescent intensity alone. However, a lack of signal consistency and a problem with gradual signal loss have limited its application as a marker for high throughput microscopy and drug screening. Its disruption of cellular activity when fused with microtubules has also limited its use in the study of the cytoskeleton.
Fusing Gene with Fluorescent Protein Provides Stronger Signal :
This technology allows the fusion of a gene of interest with several GFP sequences that is able to produce a substantially stronger signal (2-6 fold increase) that is stable and is virtually immune to photobleaching (loss of fluorescent intensity over time). In addition, a unique fusion protein has been generated that is able to label microtubules without damage to the integrity of the cell and allows for safe, long-term imaging of the microtubule network. Preliminary results indicate that fluorescence can be detected from just 1 to 10 molecules.
Applications:
• Probe specific proteins for live microscopy at the single cell level
• High throughput screens where high signal to noise ratios are important for automated image recognition programs ie a drug screen involving microscopy
• Quantification of protein expression for low-abundance proteins
• Long term or high exposure live imaging for studying dynamics of sub-cellular components
• Studies involving the tracking of the microtubule cytoskeleton dynamics
• Quantitative microscopy technique such as fluorescent speckle microscopy
• Quantitative FACS (Fluorescence-activated Cell Sorting)
Advantages:
• Brighter fluorescence signal (2-6 fold increase) per molecule
• Much more stable signal equates fluorescence intensity and actual protein expression
• Higher Resistance to photobleaching increases exposure times and allows higher sampling rate
• A unique fusion protein that can safely label microtubules
Patent Status: Patents Issued (US 5,985,577, US 6,596,475) ~ see links below.
Licensing Status: Available for Licensing and Sponsored Research Support
Publications: Bulinski JC, Gruber D, Faire K, Prasad P, Chang W. GFP Chimeras of E-MAP-115 (ensconsin) Domains Mimic Behavior of the Endogenous Protein in vitro and in vivo
(1999) Cell Struct Funct. Oct;24(5):313-20.
