Cell membranes are usually impermeable to foreign materials, which means materials like proteins and nucleic acid cannot enter the cells. The phenomenon of using an electric pulse helps in creating temporary pores in the cell membrane. This phenomenon is called electroporation.
The instrument used to create these pores is termed an electroporator. The electroporator is widely used in molecular biology, genetic engineering, and biotechnology. The basic principle of an electroporator is creating transient pores in the cell membrane by sending a brief electrical pulse.
The transient pores formed during this method allow entry of foreign genetic material inside the cell, which incorporates itself into the cell’s genome. The instrument has various designs and capacities, from small benchtops to larger-scale automated systems.
Table of Contents
Principle of Electroporator
An electroporator follows the principle of electroporation, where the use of electric pulses or electricity assist in forming pores in the membranes. These pores help in introducing foreign genetic material and proteins into the cells.
Electroporation has five fundamental principles: cell membrane permeabilization, electrical pulses, pore formation, uptake of genetic material, and cellular recovery.
- Cell Membrane Permeabilization: The cell membrane is primarily impermeable to large molecules like RNA, DNA, and proteins. The electrical pulses used by this instrument temporarily disrupt the cell membrane’s integrity. The temporary disruption creates temporary pores in the cell membrane, allowing the entry of the materials inside the cell.
- Electrical Pulses: The electroporation method applies short, high-voltage electrical pulses in the cells. The vibrations generate an electric field throughout the cell membrane. The electric field disrupts the lipid bilayer, forming temporary pores.
- Pore Formation: When the electric field is provided in the cell, the cell membrane goes through a process called dielectric breakdown. The dielectric breakdown causes lipid molecules of the cell membrane to reorient and create temporary openings and pores in the membrane.
- Uptake of Genetic Material: Once pore formation occurs, the size is large enough to enter genetic materials and proteins in the cell. DNA is drawn into the cell through these pores due to electrostatic forces.
- Cellular Recovery: The cell membrane reseals itself once the electrical pulse is withdrawn. Usually, the cells can recover in a growth medium that helps repair the membrane and resume their normal cellular functions.
However, the successful completion of electroporation depends on factors like electrical pulse voltage, durage, number, types of cells used, and the introduced genetic material’s size and type. The optimization of these parameters is critical to achieve efficient electroporation and ensure cell viability.
Parts of Electroporator
An electroporator is a complex laboratory instrument that performs electroporation to introduce foreign materials into the cells by forming temporary pores. Based on different companies, the parts of the electroporator can vary widely.
However, some of the common parts of an electroporator include a control panel, electrical pulse generator, cuvette chamber, electrodes, pulse controller, high-voltage supply, safety features, cooling systems, and adapters.
Control Panel
The control panel is the area in the laboratory instrument where the user inserts instructions for the electroporation process. It is also referred to as an interface. This part helps in controlling voltage, pulse duration, and pulse number. It may have a display screen for viewing the progress of the procedure.
Electrical Pulse Generator
This part of the laboratory instrument generates electrical pulses required for electroporation. It produces high-voltage pulses, which are delivered to the cell.
Cuvette Chamber
This is where the cell sample is added for electroporation. It usually has two electrodes where the cells are exposed to electrical pulses. The size of cuvettes vary widely to fit the different volume of the samples.
Electrodes
The instrument has two electrodes, one at each end of the cuvette chamber. The electrodes provide electrical pulses to the cell sample. The electrodes are of different types: plate, cuvette, and specialized. The specialized electrodes are specific to certain cell types.
High-voltage Supply
The high-voltage power supply sends off the necessary electrical energy for generating high-voltage pulses for electroporation. Its role is ensuring that electrical pulses are delivered at specified voltage levels.
Safety Features
Electrical isolation and interlocks are the safety features of electroporators. The electrical isolation protects the user from electrical shocks and overcurrent protection. Likewise, interlocks prevent the instrument from operating when not correctly configured.
User Manual and software
The electroporators come with a user manual that provides instructions on operation and maintenance. Modern electroporator has software for programming and controlling the instrument.
Miscellaneous Parts
- Adapters: Some electroporators may include holders or adapters. These adapters ensure the cuvettes or samples are appropriately placed for electroporation.
- Pulse Controller: Some electroporators have a separate component or module for controlling the different parameters of electrical pulse like duration, number, and voltage. This part helps in obtaining precise control of the electroporation conditions.
- Cooling Systems: Various electroporators have a cooling system for dissipating generated heat. It is crucial when dealing with multiple samples or high-throughput applications.
- Data Logging and Concetivity: New generation electroporators may have data recording capabilities for recording the parameters and outcomes of each electroporation test. Some models of electroporators may also have connectivity options like USB ports or data transferring software for data retrieval and analysis.
- Trigger: Some electroporators consist of trigger or footswitch mechanisms. This mechanism allows the user to initiate the electrical pulse delivery manually.
Although these are some of the commonly present parts of an electroporator, the specific features and details can vary between different models and brands. So, studying the user manual is vital before operating the electroporator.
Uses of Electroporator
Electroporators are widely useful laboratory instruments in various molecular biology, genetic engineering, and biotechnology fields. Whatever the field of biology, the primary use of the device is to incorporate genetic material into cells.
- Electroporators help in gene therapy research, functional genomics, and gene expression studies in mammalian cells by the process called transfection. It is also helpful in producing viral vectors by introducing viral genomes into producer cells for gene therapy and gene delivery applications.
- It is also used to introduce plasmid DNA or other genetic material in bacterial and yeast cells or transform, essential in molecular biology biotechnological applications.
- This equipment is also helpful in generating genetically modified organisms by introducing specific mutations into the genomes of these organisms.
- Likewise, this technique has successfully developed recombinant proteins by introducing targeted genetic components into the genome. This introduction helps in expressing the desired proteins.
- Electroporators are also helpful in gene editing technologies like CRISPR-Cas9 for delivering CRISPR components into the cells for editing specific genomes.
- In some cases, electroporation is useful in fusing cells, which applies to hybridoma technology producing monoclonal antibodies. It also applies to drug delivery mechanisms in pharmacology research and drug discovery.
- Electroporation is helpful in cancer research for drug screening, gene therapy, and delivery of therapeutic agents in cancer cells. Similarly, this technique is also applicable in vaccine development by enhancing the delivery of DNA-based vaccines to cells, which helps in improving immune response.
- The instrument helps introduce genes into stem cells, essential in stem cell research. In plant biotechnology, this instrument helps introduce foreign genes into plant cells for improving crops, disease resistance, and developing genetically modified crops.
Types of Electroporator
Electroporators are different types with slight variations in features, pulse parameters, voltage ranges, and other specifications. The choice of this instrument depends on the specific needs of the researchers and the types of cells and organisms used for the research. Some common types of electroporators, with brief descriptions of each.
Yeast and Bacterial Electroporators
These instruments transform yeast and bacterial cells. The bacterial electroporators are used in molecular biology research for cloning, genetic engineering, and protein expression of bacteria. These electroporators also have specialized cuvettes and parameters optimized for bacterial cells.
Plant and Mammalian Cell Electroporators
The mammalian electroporators provide the necessary flexibility and control to work on mammal cells. These instruments are helpful in transfecting mammalian cells with DNA, RNA, or other nucleic acids. These are significant in gene expression studies, gene therapy research, and gene editing. Plant electroporators are crucial for genetically modifying plant cells and tissues and can accommodate larger volumes and use specialized electrodes or cuvettes suitable for plant materials.
High-throughput electroporators
These can process multiple samples simultaneously, making the output through and at a high rate. These are applicable in drug screening or large-scale protein expression studies.
Desktop Benchtop Electroporators
These are compact instruments suitable for small-scale experiments and individual laboratories. Although close, they are versatile and commonly used for various electroporation applications.
Automated Electroporators
Various other processes within electroporation get automated in this type of electroporator, like cell handling, dispensing, and data collection. These help in high-throughput and automation of laboratories like drug discovery and genomics.
Flow Electroporators
These help enable continuous and efficient cell electroporation in a fluid stream. These are highly efficient in cell therapy and other applications requiring high cell throughputs.
Clinical and Portable Electroporators
These are used in clinical trials and potentially therapeutic purposes for gene delivery to patient’s cells during gene therapy. Some electroporators are small, portable, and designed for field applications like point-of-care diagnostics and on-site genetic modification experiments in remote locations.
References
- Electroporation. Bio. https://www.bio-rad.com/en-np/category/electroporation
- Fisher Scientific. https://www.fishersci.com/us/en/browse/90222047/electroporators
- Schmitt, M. A., Friedrich, O., & Gilbert, D. F. (2019). Portoporator©: A portable low-cost electroporation device for gene transfer to cultured cells in biotechnology, biomedical research and education. Biosensors & bioelectronics, 131, 95–103. https://doi.org/10.1016/j.bios.2019.02.024
