Use of alternating magnetic field enables contact-free cell lysis

Cell lysis – the breaking open of a cell to access its information – is often needed to properly analyze and diagnose certain infectious diseases. Traditional methods of performing cell lysis often require the use of chemical detergents, biological enzymes, or external heating blocks, which can be imprecise, expensive, and affect the integrity of samples.

Burklund et al. developed a microfluidic immunomagnetic method for performing cell lysis, which uses an alternating current magnetic field to capture and concentrate bacteria on the surface of a microchip. Their method is contact-free and enables downstream molecular characterization of bacterial nucleic acids.

“We are getting better and better at diagnosing disease, but new tools for sample preparation and nucleic acid isolation are urgently needed,” said author Alison Burklund.

By coating the diagnostic platform with a magnetic polymer, the researchers were able to use an alternating magnetic field to heat the microchip surface up to temperatures of 80-110 C, which allowed the researchers to perform thermal lysis of bacteria.

The authors explained that their approach is simple to fabricate, non-dilutive, and allows precise temperature control with low contamination risks.

“The proposed methodology allows us to detect important genetic material that one might find in a bio-fluid sample and detect infectious pathogens with increased sensitivity,” said Burkland.

By coupling their method with an upstream biomarker enrichment platform, the researchers were also able to localize biomarkers of interest on a specific region of the chip before lysis.

In the future, the researchers hope to miniaturize the source of the external magnetic field to make it more suitable for point of care applications.

Source: “Microfluidic enrichment of bacteria coupled to contact-free lysis on a magnetic polymer surface for downstream molecular detection,” by Alison Burklund, James D. Petryk, P. Jack Hoopes, and John X. J. Zhang, Biomicrofluidics (2020). The article can be accessed at https://doi.org/10.1063/5.0011908 .