APPLICATIONS OF TECHNOLOGY:

	Berkeley Lab’s colorimetric biological barcode assay. A) Probe preparation and electron micrograph images of amine-modified porous silica beads. B) Interleukin-2 detection scheme.

Ultra-sensitive detection of biological targets of interest (e.g. proteins and nucleic acids) for:

• Early disease diagnosis e.g. detecting cytokines predictive of cancers and immunodeficiency-related diseases, and amyloid-beta-derived diffusible ligands indicating Alzheimer’s disease
• Genetic testing
• Drug screening
• Bio-toxin identification

ADVANTAGES:

• Portable and simple enough to be used at point of care
• Achieves attomolar sensitivity, enabling earlier disease diagnosis and the discovery of extremely low-level biomarkers
• Results can be interpreted by a layperson
• Less expensive than existing biological barcode detection schemes
• Direct and simultaneous detection of multiple proteins and nucleic acids

ABSTRACT:

Jwa-Min Nam and Jay Groves at Berkeley Lab have developed a portable and inexpensive biological barcode amplification assay that yields results simple enough for a layperson to interpret.  The method detects 30 attomolar concentrations of an analyte, one of the most sensitive protein detection assays to date, allowing earlier and more accurate detection of diseases.  The sensitivity of the new Berkeley Lab assay is comparable to current biological barcode methods and over an order of magnitude more sensitive for cytokine detection than enzyme-based rolling cycle amplifications.

While earlier biological barcode amplification protocols have sensitivity comparable to PCR for protein and nucleic acid targets without requiring time and instrument intensive enzymatic amplification, they still depend on complicated instrumentation and processing steps such as microarrayers, silver enhancement of immobilized nanoparticles on a chip, and chip imaging equipment.  By using larger and porous barcode probes, the Berkeley Lab invention dramatically increases the number of barcode DNA per probe, which amplifies the signal enough to enable the use of less complex gold nanoparticle barcode DNA detection methods in which analyte detection and concentration can be determined simply by color change on a thin layer chromatography chip.  The Berkeley Lab inventors have also developed an easy method for quantifying spot intensity using graphic software.

In addition to early disease diagnosis, the advantages of the new assay method extend to genetic testing, drug screening, and bio-toxin identification.

STATUS:

• Published Patent Application.  Available for licensing or collaborative research.

FOR MORE INFORMATION SEE:

Nam, J.-M., Wise, A., Groves, J.T., “Colorimetric Bio-Barcode Amplification Assay for Cytokines,” Anal. Chem. 2005, 77, 6985-88.

REFERENCE NUMBER: IB-2184

SEE THESE OTHER BERKELEY LAB TECHNOLOGIES IN THIS FIELD:

• Quantum Dot Based Cell Motility, Invasion, and Metastasis Assays, IB-1755
• Regulatory Sequence that Controls the Expression of Allergic-Related Cytokines, IB-1584