Electrophoresis plays an essential role in modern molecular biology, genetics, biotechnology and protein research. From checking PCR products to analysing protein expression, this technique helps scientists separate and examine biological molecules.
However, not all electrophoresis systems perform the same applications. Choosing between horizontal and vertical equipment depends on the sample type, separation method and intended analysis. Furthermore, selecting the correct gel dimensions, sample capacity and power supply can significantly improve laboratory efficiency.
At Apex Scientific, we supply electrophoresis equipment to laboratories throughout South Africa, including horizontal and vertical systems from JeioTech.This article explores how electrophoresis works, its most common applications and the important factors to consider before purchasing equipment.
What Is Electrophoresis and How Does It Work?
Electrophoresis is a laboratory technique that separates charged molecules by applying an electrical field through a supporting medium, usually a gel. Scientists commonly use this technique to analyse DNA, RNA and proteins. During gel electrophoresis, researchers load samples into small wells within a gel. An electrical current then moves charged molecules through the gel matrix. The gel acts as a molecular sieve. Consequently, molecules migrate at different rates depending on their size, charge and the separation conditions.
For example, DNA molecules carry a negative charge due to their phosphate backbone. Therefore, they migrate towards the positive electrode during electrophoresis.
Smaller DNA fragments generally travel faster through agarose gels than larger fragments. However, proteins behave differently because their natural charges and structures vary. Researchers commonly use SDS-PAGE to give proteins a broadly uniform negative charge relative to their mass.
As a result, SDS-PAGE separates proteins primarily according to molecular weight.After separation, researchers visualise the resulting bands using suitable stains and imaging equipment.
Horizontal vs Vertical Electrophoresis: What’s the Difference?
One of the most important purchasing decisions involves choosing between horizontal and vertical electrophoresis systems. Although both techniques use an electrical field to separate molecules, their applications and gel configurations differ.
Horizontal Electrophoresis for DNA and RNA Analysis
Horizontal electrophoresis systems typically use agarose gels to separate DNA and RNA fragments. The gel sits horizontally inside a buffer-filled tank. Once researchers load their samples, an electrical current moves the molecules through the gel.This method is particularly popular in molecular biology laboratories because it offers a straightforward and cost-effective approach to nucleic acid analysis.
Common applications include:
- PCR product verification
- DNA fragment size analysis
- Restriction enzyme digestion analysis
- Plasmid DNA analysis
- RNA integrity assessment
- Certain genotyping applications
For example, researchers performing PCR can use electrophoresis to confirm whether amplification produced a DNA fragment of the expected size. Similarly, laboratories conducting restriction enzyme digestion can compare fragment patterns against a DNA ladder.
However, conventional agarose electrophoresis does not provide the same fragment-sizing precision as automated capillary electrophoresis systems.
Vertical Electrophoresis for Protein Analysis
Vertical electrophoresis systems typically use polyacrylamide gels for protein separation. Unlike horizontal systems, these gels sit vertically between glass plates. This configuration supports techniques such as SDS-PAGE and Native PAGE. SDS-PAGE is particularly useful because it separates proteins primarily according to molecular weight. Consequently, researchers can compare protein band patterns, estimate molecular weights and assess sample purity.
Common applications include:
- Protein molecular weight determination
- Protein purity assessment
- Protein expression studies
- SDS-PAGE
- Native PAGE
- Protein separation before Western blotting
Additionally, vertical electrophoresis systems can form part of a complete Western blotting workflow. However, protein separation and Western blotting are not identical processes. Western blotting requires an additional transfer step, followed by antibody-based detection.
Understanding Western Blotting and Protein Transfer
Western blotting is a widely used technique for identifying specific proteins within complex biological samples.
The process generally involves three main stages.
1. Protein Separation
Researchers first separate proteins using SDS-PAGE. During electrophoresis, proteins migrate through a polyacrylamide gel according to their molecular weight.
2. Protein Transfer
Next, researchers transfer the separated proteins onto a nitrocellulose or PVDF membrane. An electrical field drives proteins from the gel onto the membrane.
3. Protein Detection
Finally, researchers use antibodies to identify their target proteins. Depending on the detection method, the resulting signal may be chemiluminescent, fluorescent or colorimetric.
For chemiluminescent detection, laboratories typically use a compatible Western blot imaging system.Therefore, customers planning Western blotting should consider both the electrophoresis system and the additional equipment required for transfer and detection.
JeioTech Horizontal Electrophoresis Systems: EP-05, EP-10 and EP-18
JeioTech offers three horizontal electrophoresis systems designed for different gel dimensions and sample throughput requirements.
The EP Series includes the EP-05, EP-10 and EP-18.Although all three systems support agarose gel electrophoresis, their sizes and capacities differ.
| Model | Gel Tray Dimensions | Buffer Capacity | Typical Application |
| EP-05 | 82 × 57 mm or 82 × 81 mm | 0.5 L | Small-scale DNA/RNA analysis |
| EP-10 | 180 × 102 mm | 1.0 L | Routine molecular biology |
| EP-18 | 180 × 205 mm | 1.8 L | Higher-throughput DNA/RNA analysis |
EP-05: Compact Electrophoresis for Smaller Workloads
The EP-05 offers a compact solution for laboratories processing relatively small numbers of samples.
Its smaller gel dimensions make it suitable for teaching laboratories, routine PCR verification and basic molecular biology applications.Furthermore, its 0.5 L buffer capacity helps minimise buffer consumption compared with larger systems.
EP-10: Versatile Electrophoresis for Routine Applications
The EP-10 provides a larger gel format for laboratories requiring greater sample capacity.
It offers a practical balance between benchtop space, gel dimensions and sample throughput.Consequently, it suits research laboratories performing routine DNA analysis, restriction digestion and PCR product screening.
EP-18: Electrophoresis for Higher Sample Throughput
The EP-18 accommodates larger gels, making it suitable for laboratories processing more samples per run. Its larger separation area provides greater flexibility when arranging multiple sample lanes. Therefore, it may benefit laboratories conducting routine screening or larger molecular biology projects.
All three models incorporate polycarbonate tanks and lids, platinum-wire electrodes, gel casting accessories and sample combs. However, customers should confirm their preferred comb configuration and sample capacity before ordering.
The power supply is also a separate purchasing consideration.For additional technical specifications, visit the JeioTech EP Series manufacturer page.
Internal product link: Horizontal Gel Electrophoresis Systems
JeioTech Vertical Electrophoresis Systems: VEP-4G and VEP-TB
For protein analysis, JeioTech offers the VEP-4G and VEP-TB vertical electrophoresis systems. Both models support protein separation using compatible polyacrylamide gels.
Furthermore, both systems accommodate up to four gels simultaneously. However, their main difference involves protein transfer functionality.
VEP-4G: Protein Separation
The VEP-4G supports routine protein electrophoresis applications, including SDS-PAGE. Researchers can use the system to separate proteins, estimate molecular weights and examine protein band patterns.
Additionally, its multiple-gel capacity allows laboratories to process several samples or experimental groups during one run. This makes the VEP-4G suitable for laboratories that already own separate protein transfer equipment or only require protein separation.
VEP-TB: Protein Separation and Western Blot Transfer
The VEP-TB combines vertical electrophoresis and protein transfer functionality. Consequently, researchers can perform both processes using the same tank with the appropriate internal modules. This arrangement reduces the need for separate electrophoresis and transfer tanks.
Furthermore, the system supports a more integrated Western blotting workflow. However, laboratories still require suitable membranes, antibodies, detection reagents and imaging equipment to complete the analysis.
JeioTech also offers different comb configurations, allowing users to select well numbers and thicknesses according to sample requirements.For detailed specifications, explore the JeioTech Vertical Electrophoresis Systems.
Internal product link: Vertical Gel Electrophoresis Systems
Why the Electrophoresis Power Supply Matters?
Every electrophoresis system requires a compatible power supply to generate the electrical field needed for separation. However, power supplies differ in voltage, current, power capacity and operating modes.
Therefore, selecting a suitable power supply is just as important as choosing the correct tank.The JeioTech EPS-300 is a multipurpose power supply designed for nucleic acid electrophoresis, protein electrophoresis and compatible protein transfer applications.
Key Features of the EPS-300
| Feature | Specification |
| Voltage range | 5–250 V |
| Maximum current | 3,000 mA |
| Maximum power | 300 W |
| Operating modes | Constant voltage or constant current |
| Output connections | Four pairs of parallel terminals |
| Timer | 1 minute to 99 hours, 59 minutes |
| Additional functionality | Pause/resume |
The EPS-300 also includes safety features and supports multiple electrophoresis cells, provided their combined electrical requirements remain within the unit’s limits.
For example, laboratories performing several routine DNA electrophoresis runs may benefit from the multiple output connections. However, users must confirm the total current and power requirements before connecting several systems. Similarly, Western blot transfer applications may require different electrical settings from routine gel separation.
Explore the JeioTech EPS-300 Electrophoresis Power Supply for additional specifications.
Internal product link: Electrophoresis Power Supply
Seven Questions to Ask Before Purchasing Electrophoresis Equipment
Selecting the correct electrophoresis equipment starts with understanding the intended application. Before requesting a quotation, consider the following questions.
1. Are You Analysing DNA, RNA or Proteins?
This is the most important consideration. DNA and RNA analysis generally requires horizontal agarose gel electrophoresis.
In contrast, protein analysis commonly requires vertical polyacrylamide gel electrophoresis.However, specialised techniques may require alternative configurations.
2. Do You Need a Horizontal or Vertical System?
Once you establish the sample type, confirm the separation technique.
For example, PCR product analysis generally requires a horizontal system.Conversely, SDS-PAGE requires a suitable vertical system.
3. What Sample Capacity Do You Require?
Consider how many samples you need to process during each run. For horizontal electrophoresis, smaller workloads may suit the EP-05, while larger workloads may benefit from the EP-10 or EP-18.
For vertical electrophoresis, the VEP Series accommodates up to four gels.However, the actual number of samples depends on the selected comb configuration.
4. What Gel Dimensions Do You Need?
Gel dimensions influence sample capacity and separation distance. Therefore, confirm the preferred gel size before selecting a system.
For vertical electrophoresis, also establish whether the laboratory uses hand-cast or precast gels.Importantly, not every precast gel format is compatible with every vertical system.
5. Will You Be Performing Western Blotting?
If the application involves protein analysis, determine whether protein transfer is necessary.
For separation only, the VEP-4G may be suitable.However, customers requiring both protein separation and transfer should consider the VEP-TB.
6. Do You Already Have a Power Supply?
Some laboratories already own electrophoresis power supplies. Nevertheless, compatibility should never be assumed.
Check the existing unit’s voltage, current, power capacity and electrical connections.If necessary, consider the EPS-300 as part of a complete solution.
7. How Will You Visualise Your Results?
Electrophoresis separates molecules, but researchers still need a suitable detection method. For DNA and RNA analysis, laboratories commonly use fluorescent stains and gel documentation systems.
For protein analysis, researchers may use Coomassie staining, silver staining or fluorescent stains.
Meanwhile, Western blotting may require chemiluminescent or fluorescent imaging.Therefore, consider imaging requirements before finalising the equipment purchase.
Common Electrophoresis Purchasing Mistakes
Even experienced laboratories can overlook important requirements when purchasing electrophoresis equipment.
Choosing the wrong system type: Horizontal agarose systems and vertical protein systems serve different primary applications. Therefore, always establish the separation technique first.
Underestimating sample capacity: A smaller system may appear cost-effective initially. However, insufficient sample capacity can increase the number of runs and reduce laboratory productivity.
Ignoring gel compatibility: Existing precast gels may not fit a new electrophoresis system. Consequently, customers should confirm dimensions and cassette compatibility.
Overlooking power supply requirements: Not all power supplies support every electrophoresis or transfer method. Therefore, check electrical specifications before purchasing.
Forgetting imaging equipment: Gel separation alone does not provide a permanent record of results. Laboratories should consider suitable staining and imaging equipment as part of their workflow.
Confusing Western blotting with protein electrophoresis: SDS-PAGE separates proteins, while Western blotting adds transfer and antibody-based detection. Consequently, a complete Western blotting workflow requires additional components.
Conclusion
Selecting the correct electrophoresis system involves more than choosing between horizontal and vertical equipment. Researchers must also consider sample throughput, gel dimensions, power requirements and detection methods.
At Apex Scientific, we help laboratories across South Africa identify suitable equipment for their molecular biology and protein research applications. Our range includes JeioTech horizontal electrophoresis systems, vertical protein electrophoresis systems and compatible power supplies.
Furthermore, we can assist customers in identifying suitable gel imaging and Western blot detection solutions.
Whether your laboratory performs routine PCR analysis, DNA fragment separation, SDS-PAGE or Western blotting, our team can help you evaluate the available options. Contact Apex Scientific to discuss your electrophoresis requirements and request a quotation for a solution suited to your application.
