Microfluidic chip for growth visualization of Mycobacterium smegmatis at single-cell resolution

The Mycobacterium tuberculosis, the pathogen causing tuberculosis has a multi-layered cell wall that regulates the metabolite transfer through the membrane and prevents antibiotics from entering the cell. Mycobacterium tuberculosis (Mtb) can adapt its growth rate according to the available nutrients in the environment. Previous studies have not been successful in fully understanding the mechanism by which the Mtb enters a nonreplicative state. A better understanding of this adaptation mechanism can help us find more efficient ways to defeat this pathogen. Microfluidics has shown great promises in single-cell analysis and hence can be a good candidate for this purpose. 

A recent research published in Microsystems & Nanoengineering reports a microfluidic chip for long-term growth visualization of living cultures of Mycobacterium smegmatis at single-cell resolution.

“Here, we developed a single-cell-resolution microfluidic mycobacterial culture device that allows time-lapse microscopy-based long-term phenotypic visualization of the live replication dynamics of mycobacteria. This technology was successfully applied to monitor the real-time growth dynamics of the fast-growing model strain Mycobacterium smegmatis (M.smegmatis) while subjected to drug treatment regimens during continuous culture for 48 h inside the microfluidic device.”, the authors explained.

The reported microfluidic chip is microfabricated using PDMS and consists of an inlet, an outlet, 29 perfusion microchannels, and 29 shallow culture microchambers. The perfusion microchannels are used to deliver the cells to the culture microchambers and expose them to flow conditions. The perfusion microchannels are 14 μm in height while the rectangular microchambers (460 μm× 300 μm in size) are around 0.9 μm. The small size of the microchambers helps in trapping the single cells. The experiment began by introducing the cells to the microfluidic device and ensuring successful rapping of the cells in the microchambers. Then, the culture media was switched to contain test drugs. The phenotypic changes of the single-cells after the treatment were tracked under the microscope to examine the capability of the bacteria to resume regular activity after exposure.

The chip was shown to be capable of long-term culture and visualization of the mycobacterial cells under perfusion conditions.

“In conclusion, our study demonstrates that the newly developed microfluidic device is capable of successful longterm growth and phenotype monitoring of rod-shaped mycobacteria. We expect that this microfluidic device technology will substantially change how clinicians and scientists can identify the correct sequence and combination of antibiotics to tailor the treatment of TB patients to significantly reduce treatment relapses or death.”, the authors concluded.


Read the original article: Development of single-cell-level microfluidic technology for long-term growth visualization of living cultures of Mycobacterium smegmatis


Pouriya Bayat

Pouriya Bayat

Pouriya is a microfluidic production engineer at uFluidix. He received his B.Sc. and M.A.Sc. both in Mechanical Engineering from Isfahan University of Technology and York University, respectively. During his master's studies, he had the chance to learn the foundations of microfluidic technology at ACUTE Lab where he focused on designing microfluidic platforms for cell washing and isolation. Upon graduation, he joined uFluidix to even further enjoy designing, manufacturing, and experimenting with microfluidic chips. In his free time, you might find him reading a psychology/philosophy/fantasy book while refilling his coffee every half an hour. Is there a must-read book in your mind, do not hesitate to hit him up with your to-read list.