49 designed a hydrodynamic trap array that split the flow cell into individual channels, and by utilizing channel focusing with small capture structures with drainage channels, was able to quickly trap single cells using only gravity driven flow, ultimately achieving ~70% trapping efficiency and 90% fill factors

49 designed a hydrodynamic trap array that split the flow cell into individual channels, and by utilizing channel focusing with small capture structures with drainage channels, was able to quickly trap single cells using only gravity driven flow, ultimately achieving ~70% trapping efficiency and 90% fill factors. of solution that help to reduce sample loss and cost of reagents. Additionally, they are highly automatable with the ability to be multiplexed to create high-throughput assays. These features of microfluidics make it an ideal platform to analyze the heterogeneity of single cells.1, 2 Microfluidics takes different forms and shapes. There are two primary forms of microfluidics: channel microfluidics and droplet microfluidics. Channel microfluidic systems utilize microscale channels and chambers that allow for all flow to be in the laminar regime. The laminar flow allows for highly reproducible and well understood flow patterns within the microfluidic structures. These devices are typically manufactured using polydimethylsiloxane (PDMS), etched glass, or silicon which is then bonded to glass. Many channel microfluidic technologies make use of multi-layer soft lithography, which allows the use of a channel for sample flows and a layer that consists of valves to manipulate the sample flow through the use of an applied pressure. 3, 4 In contrast, droplet microfluidics utilizes the immiscibility of water and oil to create pico- and nanoliter scale droplet microreactors.5, 6 The ease and speed of generation combined with simple encapsulation of single cells by using a dilute suspension makes it the ideal high-throughput technology for single cell analysis.7, 8 Individual droplets can be transported, merged, mixed, and divided using on-chip processes. 5 Additionally, the generation of unique barcodes in single droplets makes pooling samples for data analysis much simpler.9C12 Digital microfluidics (DMF) is a subset of droplet microfluidics, also known as electrowetting on dielectric (EWOD), which is a different technological approach to developing Benfotiamine lab-on-chip systems.13, 14 EWOD systems are made up of separate surfaces that are able to change hydrophobicity when applied with an electric field. An array of these surfaces allow for the movement and manipulation of droplets of solution. Single cell analysis has been gaining attention and popularity in recent years. There is a known heterogeneity to exist within a population of seemingly identical cells.15, 16 This is particularly important when primary cell samples from lab animals and patients are concerned. For this reason, it is important to study individual cells to understand the complex biology of the heterogeneous population. These minute differences in cellular activities could be essential in the development of personalized medicine and disease research. The ability to analyze a population of cells to Benfotiamine isolate drug resistant cells for further analysis is one of the most important applications for developing effective therapeutic methods. 17 The methods for single cell analysis are broad and include everything from measuring physical properties of cells, to protein analysis, deciphering cell signaling, and DNA/RNA sequencing. Using these examinations it is possible to make previously unknown breakthroughs by looking at rare tumor cells such as circulating tumor cells 18, 19. It can additionally be used Benfotiamine to study cancer stem cells in order to understand the disease PPARG progression and make more effective chemotherapeutics 20, 21. Earlier developments for single cell analysis began primarily with cytometric analysis of single cells, rapidly testing fluorescent labeled cells inside a circulation 22, 23. As the field offers developed, microfluidics allowed for any much wider range of analysis that would not become economical or feasible using a traditional platform. For example, further developments in solitary cell proteomic analysis were brought through the controlled breakage of solitary cells and further analysis of their material. 24, 25 This review of microfluidic solitary cell analysis Benfotiamine will cover recent developments ranging from solitary cell sample collection to numerous examination methods (physical, chemical, molecular/nucleic acid analyses). These.