In molecular biology laboratories around the world, horizontal gel electrophoresis is a foundational technique for DNA and RNA separation. Whether analyzing PCR products or verifying restriction digests, the accuracy of your results depends heavily on one key factor: the proper operation of the electrophoresis apparatus. Behind every sharp DNA band is a series of carefully executed steps and maintenance habits that make the difference between clean results and experimental failure.
In this article, we unveil the essential secrets to mastering your horizontal electrophoresis system, helping researchers worldwide achieve reproducible, high-quality outcomes.
1. Start with a Clean and Intact Gel Tray
Contamination or micro-cracks in the gel tray can distort electric fields, affecting migration. Before each run:
Rinse the gel tray and combs with distilled water.
Check for any warping or surface residues.
Ensure combs are not damaged or misshaped.
Tip: Never clean with harsh solvents or rough materials that might scratch the tray surface.
2. Precise Gel Preparation and Casting
The uniformity and consistency of the agarose gel influence resolution. Key practices include:
Use high-purity agarose appropriate for the target DNA size.
Ensure the gel is fully set before moving or placing in the tank.
Avoid bubbles during pouring; they can create pockets that trap samples.
Tip: Always insert combs at a consistent angle to avoid air gaps.
3. Use Fresh, Properly Diluted Running Buffer
The buffer conducts current and stabilizes pH. Make sure to:
Use freshly prepared TAE or TBE buffer.
Fill the chamber just enough to submerge the gel but not flood the system.
Maintain consistent buffer concentration across the gel and reservoir.
Tip: Reusing buffer repeatedly leads to ion depletion and uneven migration.
4. Correct Sample Loading Technique
Accurate sample loading prevents cross-contamination and ensures proper migration:
Load slowly with steady hands.
Use the right pipette tips or loading tips compatible with the gel thickness.
Mix loading dye well with DNA samples to monitor progress.
Tip: Practice loading with dye-only samples if you are new to electrophoresis.
5. Set the Right Voltage and Time
Voltage affects migration speed and band sharpness. For standard DNA separation:
Run at 5–10 V/cm (measured between electrodes).
Monitor temperature; high voltages can melt the gel or denature DNA.
Never leave the unit unattended for long periods.
Tip: For fine band separation, opt for lower voltage and longer run times.
6. Ensure Proper Connection and Polarity
Always double-check electrode connections:
DNA migrates toward the positive (red) electrode.
Connect cables firmly and verify the power indicator.
Mismatched polarity leads to samples migrating in the wrong direction.
Tip: Mark the loading wells end to avoid orientation errors.
7. Regular Maintenance of Electrophoresis Apparatus
Preventive maintenance extends the lifespan of the unit:
Wipe down the tank and lid after each use.
Inspect electrodes for corrosion or wear.
Store in a dry, dust-free environment.
Tip: Document routine checks to catch equipment issues early.
If you have any questions about horizontal electrophoresis experiment, feel free to visit our website or contact our professional team. We are committed to providing you with the best solutions!
Beijing Liuyi Biotechnology Co., Ltd. (Liuyi Biotechnology) has over 50 years of expertise in manufacturing electrophoresis instruments. With a dedicated technical team and R&D center, we provide reliable and comprehensive production, from design to inspection and warehousing. We offer a full range of products, including:
- Electrophoresis Cells (Tanks/Chambers)
- Electrophoresis Power Supplies
- Blue LED Transilluminators
- UV Transilluminators
- Gel Imaging & Analysis Systems
In addition, we supply other laboratory instruments such as PCR machines, vortex mixers, and centrifuges.
If you are considering purchasing our products, please don’t hesitate to reach out. You can contact us via email at sales@ly.com.cn or info@ly.com.cn. Alternatively, feel free to call us at +86 15810650221, add us on WhatsApp at +86 15810650221, or connect with us on WeChat at 15810650221.
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Post time: May-21-2025