High-Voltage Power Supply for Isoelectric Focusing

What is the High-Voltage Power Supply for Isoelectric Focusing?

A low-current, high-voltage supply reaching about 3500 V for isoelectric focusing and immobilised pH gradient strip runs. It offers constant voltage with stepped or gradient programs, accumulates volt-hours, and is the right choice for proteomics laboratories.

Overview

Isoelectric focusing separates proteins by isoelectric point and requires high voltage, often several thousand volts, at very small currents as the gel conductivity falls. The high-voltage supply provides up to about 3500–5000 V, with current limited to 1–10 mA per strip or gel, and total power of 30–100 W. Voltage ramps, gradient steps and hold stages are programmable so that salts migrate out before the final focusing step, and volt-hours are accumulated to define completion. Strip-tray compatible connectors and high-voltage insulation protect users. A temperature-controlled focusing tray is often used alongside, and the supply can be combined with a large-format second-dimension tank for two-dimensional electrophoresis. The design focuses on stable low-current control and high isolation.

How does it work?

An electrophoresis power supply converts mains alternating current into a regulated direct-current output. A transformer or switch-mode stage steps the voltage, a rectifier and filter create DC, and a feedback loop holds one chosen variable constant. Because the electrical resistance of a gel changes during a run as ions migrate and buffer heats, the three quantities voltage, current and power are linked by Ohm's law and P = V x I. Constant voltage gives predictable field strength, constant current keeps migration speed steady, and constant power limits heating. Most supplies switch automatically to a limiting mode when a set limit is reached. Key features include multiple outputs, programmable multi-step runs, timers, amp-hour accumulation, no-load and short-circuit detection, and isolated outputs with safety interlocks.

What are the key features?

• Output to about 3500 V with stable control at currents of 1–10 mA per strip
• Programmable ramp, gradient and hold steps support standard IPG focusing protocols
• Accumulated volt-hour counter defines focusing completion independent of resistance changes
• Current limit per strip tray prevents overheating and strip burning in high-conductivity samples
• High-voltage insulated connectors and lid interlock protect operators from exposure
• Memory stores dozens of protocols for 7, 11, 13, 18 and 24 cm IPG strips

What are the technical specifications?

A typical high-voltage power supply for isoelectric focusing configuration offers output voltage of up to 3500 V DC (5000 V option), output current of 0.01–10 mA (300 mA at lower voltage), maximum power of 30–100 W, operating modes of Constant voltage with current and power limits, programmable steps of up to 9 steps (step, gradient, hold) and volt-hour range of 0–99,999 Vh. 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 High-Voltage Power Supply for Isoelectric Focusing is used in isoelectric focusing of proteins, first dimension of 2D electrophoresis, IPG strip rehydration and focusing and isoelectric point determination. Across the wider Power Supplies class, laboratories also deploy it for agarose gel electrophoresis, SDS-PAGE and native PAGE and western blot transfer.

Which standards and certifications apply?

Relevant standards and methods include IEC 61010-1, IEC 61326-1, IEC 61010-2-010, ISO 17025 and 21 CFR Part 11. Certification candidates for this model are CE, ISO 9001 manufacturing and RoHS; each is to be confirmed for the specific configuration before shipment, and certificates are supplied only where they have been issued.

Place the supply on a dry bench away from splash and buffer spills, and never operate it with damaged leads. Connect cables with the supply switched off and respect polarity colours. Use only tanks with interlocked lids and shrouded connectors rated for the output voltage. Verify output accuracy periodically against a calibrated meter, and keep vents clear for cooling. Output above 60 V DC is hazardous, so staff should be trained and local electrical safety rules followed. Safety compliance is typically based on IEC 61010-1 and EMC on IEC 61326-1. For regulated laboratories, schedule calibration, keep service records and store run parameters where data integrity is required.

How do I select the right High-Voltage Power Supply for Isoelectric Focusing?

Select a high-voltage focusing supply for IEF and IPG strip work, not for standard gels that need high current. Specify maximum voltage, current resolution at low values, number of programmable steps, volt-hour capability, number of outputs and tray-connector compatibility.

How does it compare with other Power Supplies variants?

Match the power supply to the most demanding application. Gel electrophoresis of DNA usually needs up to 300 V and 400 mA, protein and blotting work need higher current, and isoelectric focusing or sequencing need 2000–5000 V at low current. Decide whether constant voltage alone is sufficient or constant current and power modes are also needed. Programmable multi-step protocols, such as ramped focusing, require memory and stepping. Count how many tanks run together, because multiple outputs share total power. Look for clear displays, automatic overload, no-load and short-circuit protection, isolation from earth, and compliance with IEC 61010-1. Check connector type and whether cables are compatible with your tanks, and consider remote-control or USB options for documentation.