Denaturing Urea-PAGE System for Oligonucleotide Analysis

What is the Denaturing Urea-PAGE System for Oligonucleotide Analysis?

A vertical electrophoresis system with heated plates and urea-denaturing gels that resolves short single-stranded nucleic acids differing by one base. It is used for oligonucleotide synthesis quality control and small RNA analysis.

Overview

The denaturing urea-PAGE system uses a vertical cassette with a thin gel of 15 to 20 percent polyacrylamide containing 6 to 8 M urea, which keeps single-stranded nucleic acids denatured so that migration depends mainly on length. The apparatus includes aluminium or glass heat-distributing plates, a thermostatic circulator or resistive heater that holds 45 to 60 °C, and a buffer chamber with upper and lower reservoirs. Typical loading is 0.2 to 5 nmol of oligonucleotide, and bands are visualised by UV shadowing, intercalating stains or fluorescent labels, with resolution of single-base differences in fragments of 10 to 100 nucleotides. Runs take 1 to 3 hours, and gels are cast in-house between glass plates or purchased precast. Careful plate cleaning and even heating prevent smiling bands and gel tearing.

How does it work?

In electrophoresis, an electric field drives charged molecules through a gel matrix: nucleic acids carry a negative charge from their phosphate backbone and migrate toward the anode, while their size and conformation determine how quickly they pass through the pores. Agarose gels of 0.5 to 2 percent resolve fragments from about 100 bp to 20 kb, and a buffer such as TAE or TBE carries the current between electrodes. Voltage is set per centimetre of gel length, commonly 5 to 10 V/cm, because higher voltages accelerate runs but heat the gel and blur bands. Sample loading dye adds density and tracking dyes, and a size marker gives fragment lengths by comparison. Detection uses intercalating stains under UV or blue light, or fluorescent labels in chip systems. Denaturing urea-PAGE resolves single-base differences in short oligonucleotides.

What are the key features?

• Vertical cassette for 15 to 20 percent urea-polyacrylamide gels.
• Heated plates maintaining 45 to 60 °C during the run.
• Resolution of single-base differences in short fragments.
• Supports UV shadowing and fluorescent detection.
• Precast or in-house cast gels in multiple thicknesses.
• Buffer recirculation option for stable pH.

What are the technical specifications?

A typical denaturing urea-page system for oligonucleotide analysis configuration offers gel format of Vertical, 15-20 percent polyacrylamide with 6-8 M urea, gel dimensions of 16 cm × 18 cm to 20 cm × 40 cm, gel thickness of 0.4, 0.75 or 1.0 mm, operating temperature of 45-60 °C via heated plate, voltage range of 500-2,000 V and typical run time of 1-3 h. Values are indicative of the product class; the exact figures for each configuration are confirmed on the quotation and the calibration documents supplied with the instrument.

Which applications is it used for?

The Denaturing Urea-PAGE System for Oligonucleotide Analysis is used in oligonucleotide synthesis quality control, small RNA and siRNA analysis, aptamer and primer purity checking and single-base resolution of short labelled probes. Across the wider Electrophoresis class, laboratories also deploy it for PCR product verification, DNA fragment sizing and restriction mapping and next-generation sequencing library quality control.

Which standards and certifications apply?

Relevant standards and methods include IEC 61010-1, IEC 61010-2-081, IEC 61326-1, ISO 13485 manufacturing and CLSI MM13-A. Certification candidates for this model are CE, ISO 9001 manufacturing and IEC 61010-1 test report; each is to be confirmed for the specific configuration before shipment, and certificates are supplied only where they have been issued.

Prepare gels in a dedicated area and pour them on a level surface. Use fresh buffer at the recommended dilution, since reused buffer changes pH and conductivity, and check that electrode wires and connectors are clean. Keep the tank covered during runs to limit evaporation and protect operators from UV or electrical hazards, and never touch buffer or electrodes while a run is active. Choose low-toxicity stains where possible and follow local disposal rules for ethidium bromide or other intercalating agents. Clean and rinse tanks after each run to remove residual stain and agarose. Verify power supply calibration and check for cracked gel trays, worn leads and loose lid interlocks at fixed intervals.

How do I select the right Denaturing Urea-PAGE System for Oligonucleotide Analysis?

Select this system when short single-stranded nucleic acids must be resolved to one base, as in oligo QC or siRNA analysis. Compare gel size against the resolution you need, confirm that the heating plate can hold the required temperature, and check whether precast gels are available in your thickness. Include a compatible high-voltage power supply and detection method in the planning.

How does it compare with other Electrophoresis variants?

Match the method to the molecule and the resolution needed. Agarose in a horizontal tank is standard for double-stranded DNA fragments and PCR products, denaturing urea-PAGE for oligonucleotides and single-stranded fragments, and sieving-polymer chip systems for accurate sizing and quantification of many samples. Throughput then decides between manual tanks, multi-channel units and automated systems that combine running and imaging. Consider gel format and well count, buffer volume and cooling, and the detection method, because stains, UV exposure and fluorescence optics differ in sensitivity and safety. For power supplies, check voltage, current and power limits, programmability, and whether constant voltage, constant current or constant power modes are available.