Dielectrophoresis

Definition

Dielectrophoresis is the movement of particles in a non-uniform electric field due to the polarization effects induced by the field on the particles. This phenomenon can be harnessed in microfluidic systems to manipulate and control the movement of cells and other small particles, enabling various applications such as sorting, trapping, and analyzing biological samples.

5 Must Know Facts For Your Next Test

1. Dielectrophoresis can differentiate between particles based on their dielectric properties, allowing for selective manipulation of different types of cells or particles.
2. In microfluidic devices, dielectrophoresis can be used to create precise control over particle positioning and flow within a microchannel.
3. The effectiveness of dielectrophoresis depends on factors such as particle size, shape, and the frequency of the applied electric field.
4. It can operate in both AC and DC electric fields, but alternating current is often preferred to prevent electrolysis and other issues associated with DC fields.
5. Dielectrophoresis is particularly valuable in biomedical applications, such as isolating cancer cells from blood or sorting different types of stem cells.

Review Questions

• How does dielectrophoresis enable the manipulation of particles in microfluidic systems?
  • Dielectrophoresis allows for the manipulation of particles by inducing polarization in response to a non-uniform electric field. When a particle is placed in such a field, it experiences a force that drives it toward regions of higher or lower field strength depending on its dielectric properties. This ability to control particle movement makes it an essential technique in microfluidic systems for applications like sorting and trapping cells.
• Discuss the advantages of using dielectrophoresis over traditional methods for cell manipulation in laboratory settings.
  • Dielectrophoresis offers several advantages over traditional methods like centrifugation or physical sorting. It allows for label-free manipulation, which reduces potential alterations to cell behavior or viability. Additionally, dielectrophoresis can be precisely controlled at the microscale, enabling real-time adjustments and complex operations that are difficult with conventional methods. This results in more accurate sorting and analysis of biological samples without requiring additional reagents.
• Evaluate the impact of particle size and shape on dielectrophoresis outcomes and how this influences applications in biomedical research.
  • Particle size and shape significantly affect dielectrophoresis outcomes because they determine how particles interact with the electric field. Larger particles may experience stronger forces due to increased polarization effects. Irregular shapes can lead to complex movement patterns, impacting how effectively cells can be manipulated. Understanding these influences is crucial for optimizing dielectrophoresis applications in biomedical research, where specific cell types must be isolated or analyzed accurately based on their unique properties.

Related terms

Electrophoresis: The migration of charged particles in a fluid under the influence of an electric field, commonly used in laboratory techniques for separating biomolecules.

Microfluidics: The science of manipulating and controlling fluids at the microscale, often utilized in lab-on-a-chip devices for various applications, including chemical analysis and biological assays.

Electrokinetics: The movement of colloidal particles or fluids under the influence of an electric field, encompassing both dielectrophoresis and electrophoresis as mechanisms.