Microfluidics technology has contributed to powerful tools that have helped advance many areas of biology. The applications of microfluidic systems in chemistry and biochemistry have increased in number over the years with the development of new components and processes for the injection, mixing, pumping, and storing of fluids in the microchannels.
Although microfluidic techniques have progressed in the recent years, several challenges remain in the introduction of samples and processing a range of volumes. Recent developments in nanotechnologies have helped the enhancement of microfluidic techniques. Microsystems have revolutionized the development of highly sensitive bioanalytical systems that can analyze complex samples. These devices find applications in a range of areas including clinical diagnostics, pollution monitoring, drug discovery, and biohazard detection.
Microfluidic systems are an ideal platform for biological studies due to their advantages such as low sample requirements, high surface area, and reduced system footprint. The techniques have been used to study cells as well as whole organisms. They have simplified the otherwise laborious tasks such as flow control, stimuli delivery, and animal handling.
Some micro-devices have been successfully used to study change in neuronal activity in response to spatial or temporal stimuli. Microfluidic techniques have been very helpful in sensory and locomotion behavior research in mazes. This technology has also enabled imaging, phenotyping and screening, and nerve regeneration studies.
One of the key uses of microfluidic systems is the isolation and biochemical study of single cells. In fact, studies have reported the successful measurement of β galactosidase expression in single E. coli cells using a microfluidic system.
Stem cell research
Stem cell research has immensely benefitted from advances in microfluidic technology. Miniaturization has enabled deeper stem cell analyses compared to traditional methods. Integration of this technology with tools such as fluorescent microscopy offers a more systematic way of studying stem cells and also exhibits promising medical applications.
However, some aspects of microfluidics such as the ease of use, materials used in the production of microfluidic devices, and integration with other systems need addressing so that it can be more widely applied to complex stem cell research problems.
Microfluidics allows manipulation of laminar flow of fluids in channels, thereby creating concentration gradients of several orders of magnitude. Several studies have used these gradients for analyzing the migration of neutrophils in protein gradients and the chemotaxis of human neutrophils in an interleukin-8 gradient.
When microfluidic systems are fabricated using soft lithography in agar or agarose, they form biocompatible microstructures that can act as containers and can be used to grow microbial cells in the presence of phenotype-altering molecules.
Microfluidic systems comprising crossed arrays of microchannels are used in the study of molecular interactions with cells or proteins. Such systems have been useful in many types of assays including those of pathogenic microbes and detection of proteins in serum samples.
Microfluidics has been used to devise systems capable of generating miniscule liquid droplets in the microchannels. These droplets are very tiny volumes (picoliters) and they find use in several interesting applications such as liquid bioreactors.
Microfluidic diluters perform a series of dilutions on solutions or reagents. When used in assays they behave like 96-well plates but use less reagent and are relatively easy to perform.
Microfluidic techniques have enabled otherwise impossible studies of C. elegans. New compact systems allow behavioral analysis, locomotion studies or long-term microbial culture on the chip. The novel technique helps couple worm handling and imaging which facilitates optogenetic studies and genetic screenings.
With numerous advantages such as the requirement of small volumes, reduced costs, and lesser waste generation, microfluidics makes several new investigations possible for biologists and biochemists. Going forward, microfluidics will hopefully play a greater role in developing economical methods for single-cell assays, cell-based assays, gene-expression profiling, and phenotypic screenings that can transform health care research globally.
Reviewed by Afsaneh Khetrapal BSc (Hons)