microfluidic structures for separation of bloodcells and bacteria

In this work, several lab on chip devices were designed, simulated, fabricated and tested that enable a clinically relevant sample preparation step, i.e. the separation of bacteria from a human whole blood sample. Here, passive microfluidic structures were proposed that use continuous flow separation method for the subsequent size based separation between human cells and bacteria. Since the separation process is predominantly depending on structure geometry, minimal flow tuning is required after microfabrication.

The proposed structures were simulated with Comsol Multiphysics before realized, using soft-lithography technology and PDMS. The realized structures were subjected to a variety of experiments that qualitatively and quantitatively characterize their separation performances. Fluorescence and high-speed camera measurements qualitatively showed the successful separation of suspended beads/cells to distinctive outlets. Here, simulated trajectories of beads indeed correspond to the visualized bead-tracks obtained with the high-speed camera. Furthermore, an 10x diluted mixture of normal human whole blood with B. Subtilis was introduced and successfully separated by directing the WBCs and the bacteria to distinctive outlets. Lastly, end-point efficiency measurements were conducted with a suspended beads solution and ~100% and ~60% of the introduced 10 and 2 µm beads were successfully collected at the intended outlets.

Theoretical models that were used to design the devices are hereby verified and lead to the development of a microfluidic protocol for the realization of a generic passive sample preparation module which can be tailored with design rules for specific application and has the potential to be a true enabler for automated point of care devices.

Category:

Science & Technology

Tags:

• lab on chip devices
• bacteria
• human whole blood sample
• microfluidcs
• microtechnology
• yang gao
• biology
• holland
• Twente
• university
• Philips
• comsol

[thefredsociety]

Simple, yet effective.

What flow rates are we dealing with in this experiment?

[chynaa1985]

@thefredsociety

sample flow rate in the order of 10 of ul/min dependent on the geometry.

This of course can be increased by parallel processing.

[ejsparkle]

Can you link to the papers that use these devices