CYLINDRICAL ILLUMINATION CONFOCAL SPECTROSCOPY

Unmet Need / Invention Novelty: Confocal single molecule detection (SMD) is a spectroscopic technique that plays a significant role in biological research due to its unique ability to detect and investigate the discrete properties of individual biomolecules. However, current implementations of SMD suffer from low throughput and quantification accuracy due to the non-uniform, diffraction-limited observation volume that limits practical applicability. Cylindrical illumination confocal spectroscopy (CICS) circumvents traditional SMD limitations by utilizing a planar illumination methodology that enables highly quantitative, continuous single molecule analysis.

Technical Details: Johns Hopkins researchers have developed a beam shaping optical array for single molecule detection known as CICS which permits characterization of the entire cross-section of a microchannel sample volume. Briefly, a cylindrical lens is used to perform planar, rather than Gaussian, illumination of microfluidic channels. By combining a collimated dual laser illumination beam with fluorescence spectroscopy, the fluorescent bursts of target biomolecules are digitally detected with single molecule sensitivity to increase quantification accuracy and throughput. Monte Carlo analysis and experimental demonstrations of CICS on optically characterized plasmid DNA and oligonucleotides has demonstrated that CICS rectifies the limitations of traditional confocal spectroscopy-based single molecule detection.

Value Proposition:

• New SMD implementation applicable in clinical diagnostic assays and research instrumentation
• Enables highly quantitative, continuous flow single molecular analysis with high uniformity and signal/noise ratio
• Mass detection efficiency of the observation volume approaches 100% while characterizing the entire cross section of  a standard microchannel
• Ideally suited as a platform to detect and characterize rare biomolecules such as nucleic acids, proteins, small ligands, and pathogens

Looking for Partners to: Develop & commercialize the technology as a beam shaping optical array for research instrumentation and assessment of clinical diagnostic assays.

Stage of Development: Prototype

Data Availability: Experimentally implemented.

Inventors: Tza-Huei Wang, Kelvin J. Liu

Patent Status: Granted US Patent 8,248,609

Publication(s): Liu KJ, Wang TH. Cylindrical illumination confocal spectroscopy: rectifying the limitations of confocal single molecule spectroscopy through one-dimensional beam shaping. Biophys J. 2008;95(6):2964–2975. doi:10.1529/biophysj.108.132472

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