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Single Cell Electrical Characterization Techniques.

Mansor MA, Ahmad MR - Int J Mol Sci (2015)

Bottom Line: This growing interest was supported by the emergence of various microfluidic techniques to fulfill high precisions screening, reduced equipment cost and low analysis time for characterization of the single cell's electrical properties, as compared to classical bulky technique.This paper presents a historical review of single cell electrical properties analysis development from classical techniques to recent advances in microfluidic techniques.Technical details of the different microfluidic techniques are highlighted, and the advantages and limitations of various microfluidic devices are discussed.

View Article: PubMed Central - PubMed

Affiliation: Faculty of Biosciences and Medical Engineering, Universiti Teknologi Malaysia, 81310-UTM Skudai, Johor, Malaysia. asraf@biomedical.utm.my.

ABSTRACT
Electrical properties of living cells have been proven to play significant roles in understanding of various biological activities including disease progression both at the cellular and molecular levels. Since two decades ago, many researchers have developed tools to analyze the cell's electrical states especially in single cell analysis (SCA). In depth analysis and more fully described activities of cell differentiation and cancer can only be accomplished with single cell analysis. This growing interest was supported by the emergence of various microfluidic techniques to fulfill high precisions screening, reduced equipment cost and low analysis time for characterization of the single cell's electrical properties, as compared to classical bulky technique. This paper presents a historical review of single cell electrical properties analysis development from classical techniques to recent advances in microfluidic techniques. Technical details of the different microfluidic techniques are highlighted, and the advantages and limitations of various microfluidic devices are discussed.

No MeSH data available.


Related in: MedlinePlus

(a) Illustration of a particle flowing over three electrodes inside a microfluidic channel, and a typical impedance signal for a single particle. Reprinted with permission from [75]; (b) A single cell flowing over one pair of electrode and second pair used as reference is shown. Reprinted with permission from [76]; (c) Schematic diagram of the micro impedance cytometer system, including the confocal-optical detection. Reprinted with permission from [81]; (d) Schematic of the complete microfluidic cytometer. The lock-in amplifier drives the series resonance circuit, formed by the discrete inductor and the impedance between the measurement electrodes, with an alternating current (AC) signal at a frequency close to resonance. Reprinted with permission from [82].
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ijms-16-12686-f004: (a) Illustration of a particle flowing over three electrodes inside a microfluidic channel, and a typical impedance signal for a single particle. Reprinted with permission from [75]; (b) A single cell flowing over one pair of electrode and second pair used as reference is shown. Reprinted with permission from [76]; (c) Schematic diagram of the micro impedance cytometer system, including the confocal-optical detection. Reprinted with permission from [81]; (d) Schematic of the complete microfluidic cytometer. The lock-in amplifier drives the series resonance circuit, formed by the discrete inductor and the impedance between the measurement electrodes, with an alternating current (AC) signal at a frequency close to resonance. Reprinted with permission from [82].

Mentions: Gawad et al. [75] developed a significant device in single cell impedance technology, which is known as the impedance flow cytometry (IPC). This device used coplanar electrodes to measure clear differentiation of beads and also erythrocytes and ghost cells (ghosts are RBCs that have been lysed in hypotonic buffer, leaving behind a membrane sack filled with ionic solution). As shown in Figure 4a, three microelectrodes were fabricated on the bottom of a microfluidic channel. An AC voltage was supplied to energise the electrodes for generating a non-uniform electric field within the channel. The impedance value within channel was changed, when a single cell was flowing through the detection area. This impedance value was used to characterize the electrical properties of single cell. However, this electrode configuration may affect impedance measurement when single cell was at variation position. To address this issue, K. Cheung et al. [76] designed parallel facing electrodes in a microfluidic channel (Figure 4b). One pair of parallel electrodes was used to detect cells and measure electric current fluctuation, whereas the other one was acted as a reference. Then, the difference between the two signals was measured. The device has the ability to measure electrical properties of normal RBCs and glutaraldehyde-fixed RBCs. More details for the derivation of the electric field distribution for two different electrode configurations, based on Schwarz–Christoffel Mapping (SCM) have been described [77]. In addition, a similar system (parallel facing electrodes) was used by Kampmann et al. [78] to monitor frequency effect during conducted measurement processes. The result showed that the cell can be accurately sized at around 500 kHz, where low frequency behaviour is dominated by the electrical double layer (EDL). Meanwhile, at intermediate frequencies behaviour is dominated by the membrane capacitance and at high frequencies, the cell cytoplasm becomes important. High frequency (8.7 Mhz) measurements were used to detect infection of RBCs with the parasite Babesia bovis based on the changes in the electrical properties of the cell cytoplasm [79]. Recently, an impedance flow cytometry that covers frequency range from DC up to 500 Mhz was developed by Niels Haandbæk et al. [80]. The device has a capability of dielectric characterization of subcellular components of yeast cells, such as vacuoles and cell nuclei, and can be used for discriminating wild-type yeast from a mutant.


Single Cell Electrical Characterization Techniques.

Mansor MA, Ahmad MR - Int J Mol Sci (2015)

(a) Illustration of a particle flowing over three electrodes inside a microfluidic channel, and a typical impedance signal for a single particle. Reprinted with permission from [75]; (b) A single cell flowing over one pair of electrode and second pair used as reference is shown. Reprinted with permission from [76]; (c) Schematic diagram of the micro impedance cytometer system, including the confocal-optical detection. Reprinted with permission from [81]; (d) Schematic of the complete microfluidic cytometer. The lock-in amplifier drives the series resonance circuit, formed by the discrete inductor and the impedance between the measurement electrodes, with an alternating current (AC) signal at a frequency close to resonance. Reprinted with permission from [82].
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4490468&req=5

ijms-16-12686-f004: (a) Illustration of a particle flowing over three electrodes inside a microfluidic channel, and a typical impedance signal for a single particle. Reprinted with permission from [75]; (b) A single cell flowing over one pair of electrode and second pair used as reference is shown. Reprinted with permission from [76]; (c) Schematic diagram of the micro impedance cytometer system, including the confocal-optical detection. Reprinted with permission from [81]; (d) Schematic of the complete microfluidic cytometer. The lock-in amplifier drives the series resonance circuit, formed by the discrete inductor and the impedance between the measurement electrodes, with an alternating current (AC) signal at a frequency close to resonance. Reprinted with permission from [82].
Mentions: Gawad et al. [75] developed a significant device in single cell impedance technology, which is known as the impedance flow cytometry (IPC). This device used coplanar electrodes to measure clear differentiation of beads and also erythrocytes and ghost cells (ghosts are RBCs that have been lysed in hypotonic buffer, leaving behind a membrane sack filled with ionic solution). As shown in Figure 4a, three microelectrodes were fabricated on the bottom of a microfluidic channel. An AC voltage was supplied to energise the electrodes for generating a non-uniform electric field within the channel. The impedance value within channel was changed, when a single cell was flowing through the detection area. This impedance value was used to characterize the electrical properties of single cell. However, this electrode configuration may affect impedance measurement when single cell was at variation position. To address this issue, K. Cheung et al. [76] designed parallel facing electrodes in a microfluidic channel (Figure 4b). One pair of parallel electrodes was used to detect cells and measure electric current fluctuation, whereas the other one was acted as a reference. Then, the difference between the two signals was measured. The device has the ability to measure electrical properties of normal RBCs and glutaraldehyde-fixed RBCs. More details for the derivation of the electric field distribution for two different electrode configurations, based on Schwarz–Christoffel Mapping (SCM) have been described [77]. In addition, a similar system (parallel facing electrodes) was used by Kampmann et al. [78] to monitor frequency effect during conducted measurement processes. The result showed that the cell can be accurately sized at around 500 kHz, where low frequency behaviour is dominated by the electrical double layer (EDL). Meanwhile, at intermediate frequencies behaviour is dominated by the membrane capacitance and at high frequencies, the cell cytoplasm becomes important. High frequency (8.7 Mhz) measurements were used to detect infection of RBCs with the parasite Babesia bovis based on the changes in the electrical properties of the cell cytoplasm [79]. Recently, an impedance flow cytometry that covers frequency range from DC up to 500 Mhz was developed by Niels Haandbæk et al. [80]. The device has a capability of dielectric characterization of subcellular components of yeast cells, such as vacuoles and cell nuclei, and can be used for discriminating wild-type yeast from a mutant.

Bottom Line: This growing interest was supported by the emergence of various microfluidic techniques to fulfill high precisions screening, reduced equipment cost and low analysis time for characterization of the single cell's electrical properties, as compared to classical bulky technique.This paper presents a historical review of single cell electrical properties analysis development from classical techniques to recent advances in microfluidic techniques.Technical details of the different microfluidic techniques are highlighted, and the advantages and limitations of various microfluidic devices are discussed.

View Article: PubMed Central - PubMed

Affiliation: Faculty of Biosciences and Medical Engineering, Universiti Teknologi Malaysia, 81310-UTM Skudai, Johor, Malaysia. asraf@biomedical.utm.my.

ABSTRACT
Electrical properties of living cells have been proven to play significant roles in understanding of various biological activities including disease progression both at the cellular and molecular levels. Since two decades ago, many researchers have developed tools to analyze the cell's electrical states especially in single cell analysis (SCA). In depth analysis and more fully described activities of cell differentiation and cancer can only be accomplished with single cell analysis. This growing interest was supported by the emergence of various microfluidic techniques to fulfill high precisions screening, reduced equipment cost and low analysis time for characterization of the single cell's electrical properties, as compared to classical bulky technique. This paper presents a historical review of single cell electrical properties analysis development from classical techniques to recent advances in microfluidic techniques. Technical details of the different microfluidic techniques are highlighted, and the advantages and limitations of various microfluidic devices are discussed.

No MeSH data available.


Related in: MedlinePlus