Microfluidic tools for developmental studies of small model organisms--nematodes, fruit flies, and zebrafish

Abstract

Studying the genetics of development with small model organisms such as the zebrafish (Danio Rerio), the fruit fly (Drosophila melanogaster), and the soil-dwelling nematode (Caenorhabditis elegans), provide unique opportunities for understanding related processes and diseases in humans. These model organisms also have potential for use in drug discovery and toxicity-screening applications. There have been sweeping developments in microfabrication and microfluidic technologies for manipulating and imaging small objects, including small model organisms, which allow high-throughput quantitative biological studies. Here, we review recent progress in microfluidic tools able to manipulate small organisms and project future directions and applications of these techniques and technologies.

Figure 1. Microfluidic tools for immobilization and confinement of nematodes

(A) Passive immobilization using a tapered microchannel ([20]–Reproduced by permission of The Royal Society of Chemistry); (B) microdroplet generation and trapping array ([27]–Reproduced by permission of The Royal Society of Chemistry); (C) suction-induced immobilization (Copyright 2007 National Academy of Sciences, USA [29]); (D) compressive immobilization (Reprinted by permission from Macmillan Publishers Ltd: [30] copyright 2008); (E) CO₂ immobilization ([35]–Reproduced by permission of The Royal Society of Chemistry); (F) cooling method for fully immobilization [36]; (G) passive lateral orientation [40]; (H) photoactivation of motor neurons (Reprinted from [51] with permission from Elsevier) of nematodes inside microfluidic devices.

Figure 2. Microfluidic tools for studies of fruit fly embryos

(A) Spatiotemporal control of local temperature in a fruit fly embryo with laminar flow (Reprinted by permission from Macmillan Publishers Ltd: [63] copyright 2005); (B) immobilization of embryos with oil-adhesion pads (Reproduced with permission from Springer Science and Business Media [67]); and (C) large-scale positioning and vertical orientation of fruit fly embryos [71].

Figure 3. Microfluidic tools for studies of zebrafish embryos

(A) Microfluidic segment system ([79]–Reproduced by permission of The Royal Society of Chemistry); (B) microfluidic array with drug concentration gradient generator (Reprinted with permission from [80]. Copyright 2011, American Institute of Physics); (C) microfluidic flow-through system ([85]–Reproduced by permission of The Royal Society of Chemistry).

Figure 4. Microfluidic tools for embryo transfection

(A) Electroporation in microchamber array (Reproduced with permission from Springer Science and Business Media [88]); and (B) microinjection with electroosmotic flow control ([90]–Reproduced by permission of The Royal Society of Chemistry).