Fluidigm’s Integrated Fluidic Circuit
In the 1970s engineers discovered how the same principles that spawned the semiconductor industry could be applied to liquids in life sciences. Microfluidic devices could incorporate and miniaturize complex fluid-handling steps and enhance the reliability of workflows. Early efforts tried to use silicon to create microfluidic devices based on electro-osmotic flow, but they couldn’t regulate the mixing of fluids without complicated engineering that was difficult to reproduce for high-throughput applications.
In 1998 Stephen Quake, PhD, and his group at the California Institute of Technology developed a fabrication process called Multilayer Soft Lithography (MSL®) that solved the problem. MSL used a base material of rubber and a series of channels transected by control lines that, when pressurized, deflect to create an effective seal, similar to the effect of stepping on a garden hose. More importantly, the MSL material can be used to make structures so small that tens of thousands can be integrated into a dense network of channels for regulating solutions on a micro-, nano- or even picoliter scale. Christened the Nanoflex™, this elegantly simple valve is the foundation of our IFCs, which enable consistent, accurate, scalable and economical research across a variety of genomics and proteomics applications.
Simple yet efficient design defines the Nanoflex valve, a rubber membrane that deflects under pressure to pinch off the flow of fluids in a microchannel. The valve is made from two separate layers of elastomeric rubber formed in a micro-patterned mold. By bonding the layers together, the recesses form channels and chambers in a rubber chip we call an integrated fluidic circuit, or IFC.
When pressurized liquid flows through the channels in one layer of the chip, the rubber deflects precisely at the intersection of the channels in the bottom layer, creating a simple, effective valve. Although liquid-handling robots have afforded gains in productivity for the life science industry, their value diminishes as the demand for greater throughput grows. Because of their bulk, complexity and cost, robots can’t match the ease, density and cost-effectiveness of IFCs.
Features and Benefits
- Microscopic. Nanoflex valves are so small that a single IFC can accommodate hundreds of thousands of valves, reaction chambers, channels and more.
- Precise. Reaction volumes are controlled by the chambers’ geometry, eliminating the variability associated with liquid-dispensing instruments and delivering high reproducibility rates.
- Versatile. Unlike pre-spotted biochips, IFCs enable researchers to load them in the laboratory with assays, both of their own design and pre-optimized reagents from Fluidigm.
- Clear. IFCs are made of optically clear elastomer, the material once used in contact lenses, enabling reactions to be observed as they occur.
- Gentle. Living cells within IFCs are exposed to a programmable diffusive flow, a more hospitable environment than the wells of microplates.
- Efficient. Experiments on IFCs require hundreds of times less sample and reagent than microplates because IFCs are precisely fabricated in microscopic dimensions with extremely accurate volumetric chambers.
- Gas-permeable. Because the elastomer used to make IFCs is gas-permeable, microscopic gas bubbles can't get trapped in the channels and impact results.
CyTOF® Mass Cytometry
The Fluidigm CyTOF mass cytometry systems use a novel technological approach to enable single-cell researchers to dissect intracellular networks. Most biochemistry and molecular biology knowledge assumes that the average behavior of cells in a population reflects how all cells in the populations behave. However, this assumption doesn’t appear valid when studying biological systems. Researchers are finding that stochastic fluctuations in gene or protein expression by individual cells in an otherwise identical group can lead to major differences in their behavior.
Developed by Scott Tanner, PhD, and colleagues at the University of Toronto, mass cytometry replaces the fluorophores used in traditional flow cytometry with stable, highly quantitative metal tags that are attached to specific antibodies and quantified using high-resolution mass spectrometry. CyTOF uses stable isotopes not normally found in biological systems to label antibodies and detect and quantify more than 100 different parameters per cell.
Since the 1970s the leading technique for studying and sorting cell populations has been fluorescence-based flow cytometry, which involves passing cells through flow chambers at high rates and using lasers to excite differently colored fluorescent tags attached to different antibodies, enabling researchers to quantify molecules that define cell subtypes or reflect activation of specific pathways. But there’s a problem: spectral overlap between fluorochromes limits the resolution of flow cytometry and the amount of information scientists can collect from each cell. CyTOF technology tags antibodies with different metal isotopes not naturally found in biological systems, thereby eliminating overlap of signals. Plus, more than 100 different parameters can be simultaneously measured, allowing a much higher density of information to be gathered for each cell studied.
CyTOF technology provides a high-resolution proteomic profile of each cell, which distinguishes it from all other cells and reveals the heterogeneity of the sample. This gives a more comprehensive functional and phenotypic characterization of complex systems at the single-cell level, enabling scientists to interrogate rare cells in large populations.
Features and Benefits
- The ability to detect and quantify more than 130 channels simultaneously in a single cell results in exponentially greater information.
- Simultaneous phenotypic and functional assays lead to substantial improvement in the understanding of the heterogeneity of cell states.
- Removing the limitations of spectral overlap of fluorescence and the dysfunction of fluorophores inside cells allows the targeting of more intracellular proteins at a time.
- Multiple pathway nodes can be determined simultaneously in phenotypically resolved populations.
- Full signature identification for each intact cell prevents the need to cross-correlate.
- Barcoding enables multiplexed combinatorial multiparameter screens.
- Achieving a high-resolution proteomic snapshot or profile of each cell distinguishes that cell from all others, revealing the heterogeneity of the sample.
- Comprehensive functional and phenotypic characterization of complex systems can be made at a single-cell level.
- Detailed protein signatures of individual cells can be determined from a single sample.