DVSSciences Inc.

TECHNOLOGY

Instead of using optical probes (fluorophores or quantum dots) to identify biomarkers, DVS uses elements or stable isotopes. There are more than 100 available elements and stable isotopes that are suitable for the application. The CyTOF™ uses an application-specific adaptation of an Inductively Coupled Plasma Mass Spectrometer (ICP-MS) to detect and quantify the elemental probes. ICP-MS, which is the state-of-the-art for the elemental analysis of materials, inherently offers exquisite resolution between adjacent isotope masses (more than 4 orders of magnitude), a huge dynamic range (up to 9 orders of magnitude) and provides absolute quantification.

WHY IT'S NEEDED

The technology addresses an urgent need for improvement of detection and characterization of cancer cells. This provides improved accuracy and sensitivity of diagnosis of leukemia and other diseases, which are often misdiagnosed or diagnosed too late due to the small number of markers used in detection. A high number of detected disease markers allows for personalized diagnosis and treatment.

PRODUCT APPLICATIONS: CyTOF™

Instrumentation that allows massively multiplex analysis of individual cells or beads:

clinical : accurate diagnosis of disease (or health), stem cell diseases (e.g., leukemia), risk-free alternative to amniocentesis

research : cell population characterization, gene expression, protein interaction, simultaneous gene/protein assay

gene analysis : multiplexed beads allow 1,000's of measurements per second

PRODUCT APPLICATIONS: MAXPAR™

Reagents for multiplex bioassay of bulk or discrete samples:

clinical : assay of relatively homogeneous biopsies, blood samples, and body fluids

pharmaceutical : agonist/antagonist interaction (kinase/phosphatase activity), metabolite assays, drug validation

research : protein interaction, protein reaction pathways, simultaneous gene/protein assay, high sensitivity, highly multiplexed bio assays, quality control of cell culture growth, gene expression

TECHONOLOGY OVERVIEW

Mass Cytometry is a technology that addresses applications that are typically run by flow cytometer analyzers, but extends the capability to many simultaneous parameters. The detection technology is based on atomic mass spectrometry (the state of the art technology for the determination of the elemental composition of materials, but heretofore foreign to biologists). Hence, it offers the specificity, dynamic range and quantitative capability of mass spectrometry in a format that familiar to flow cytometry practitioners.

In the cell analysis configuration, the CyTOF™ instrument "reads" the stable isotopic tags attached to antibodies using the MAXPAR™ labeling kits. Because there are many (up to 100) available stable isotopes, and the mass spectrometer provides exquisite resolution between detection channels, many parameters can be measured as easily as one – and typically without requiring compensation. Each individual cell is analyzed for any number of parameters that the user requires, and the data is downloaded into conventional flow cytometry software for examination. Massively multi-parametric cluster analysis algorithms will provide precise diagnostics for the clinician.

The same fundamental technology, replacing flow cytometry with mass cytometry, offers unique opportunities for massively multiplexed bead array analysis. Because beads can be encoded with a number of elements, the degree of multiplex is essentially unlimited (e.g., 10 elements encoded at 4 different concentrations yields one million distinguishable beads). Similar to other bead array offerings (such as XMAP by Luminex or the BD Cytometric Bead Array), the beads are conjugated to antibodies or genes for cell lysate analysis, where the binding of the target is identified by a "reporter" tag (in this instance, the MAXPAR™ tag). However, element-encoding brings the multiplex capability far beyond the fluorescence limit: bead sets of 100 to 100,000 bring the convenience of bead cytometry to the massively multiplexed challenges of SNP or targeted antigen/gene analysis. There even exists the real opportunity to conduct full 1,000,000 spot 2D-array assays in the bead cytometry format, which offers economy, simplicity and fast read-out.

Simplicity : Because the mass spectrometer provides at least 3 orders of magnitude resolution between adjacent detection channels, compensation is not required and tag-panel selection can be essentially arbitrary. Many parameters can be determined for a single cell at the same state, without requiring low-parameter sorting and re-staining with the concomitant uncertainty of cell state retention.

Versatility : The successful replacement of cytometry with mass cytometry enables translation of existing flow cytometry applications and their extension into many-dimensional analyses that until now have been inconceivable. For single cell analysis, multiple nodes in parallel translational pathways can be simultaneously measured. For bead analysis, high parameter assays that have been previously available only in expensive and challenging 2D arrays can now be addressed by cytometry.

Speed/Throughput : While the throughput is limited to about 1000 cells or beads per second, the large number of parameters that can be measured simultaneously provides a dramatic increase in the information data rate: a simultaneous 30-parameter single cell analysis corresponds to six sequential 5-parameter analyses with conventional fluorescence cytometry.

Accuracy : The Inductively Coupled Plasma Mass Spectrometer at the heart of the CyTOF™ was originally developed for the absolute quantification of elements and stable isotopes in a variety of complex matrices. The signal obtained is directly and quantitatively related to the number of atoms of the tag introduced. Accordingly, the long history and confidence of analytical chemistry is now translated to the biological arena