User:PBR1219/Label-Free Intrinsic Imaging

Label-Free Intrinsic Imaging

Label-Free Intrinsic Imaging is used for the analysis of biomolecules and utilizes a technology that avoids the need for labels commonly required in capillary electrophoresis (CE) and other related analysis techniques. Label-Free Intrinsic Imaging (LFII®) originated in particle physics but is now being applied to biochemical analysis in the capillary and microfluidic separation sciences and is adaptable to most forms of capillary electrophoresis, including capillary zone electrophoresis (CZE) and capillary gel electrophoresis (CGE). Labeled CE systems offer low limits of detection and good specificity of target interaction in complex environments but they are not able to provide multi-target imaging or any reproducibility of stain/target stoichiometry and the specialization of the dye/target relationship introduces biases that add complexity to process analytical technology (PAT) workflow and data handling.

Eliminating labels brings economic, technical and practical advantages to the established methods of CE. Label free analysis images the absorption (directly or indirectly) of the analyte itself, for example the absorption of the peptide bond that joins the amino acids that make up a protein. This removes the error inherent in using a chemical dye attached to the analyte as the visualizer, which significantly improves repeatability and quantification. This also cuts out any costs for labels or dyes, and allows analytes such as proteins to be separated in their native state permitting interactions between properly folding molecules to be performed in a CE environment. A label-free system can therefore offer improved dynamic range (concentration and molecular weight), resolution, quantification and reproducibility.

LFII® technology utilizes a multi-pixel diode array and the processing of the acquired signals from each molecular species as it traverses each pixel at a specific time point. This allows a space-time correlation called vertexing to be captured as the system measures the time taken for any one analyte to traverse the detector array. Vertexing provides a significant improvement in signal-to-noise ratio allowing for molecular imaging that exceeds canonical imaging techniques as only signals that intersect the vertex are acquired thus discriminating against system background noise. This also enables forward vertexing, allowing the collection of separated analytes for further analyses such as mass spectrometry.

Label-Free Intrinsic Imaging was developed by deltaDOT Limited, a UK-based company that was spun out in 2000 from Imperial College London. LFII® is a registered trademark and Label-Free Intrinsic Imaging is the subject of numerous patents and patent applications. Label-Free Intrinsic Imaging is considered to be a significant advance in CE technology that will make for easier and more robust CE applications, not only in biopharma but also in forensics, food and beverage, agribusiness and other industry sectors.