Buying a power supply for electrophoresis depends on your usage. For example, if several users in the lab run many gels in any given time, you may want to buy high current power supply unit. If the use is minimal you may buy a basic power supply. A good choice would be a universal power supply that could be customized based on your requirement. Bio-Rad and Hoefer both offer great power supply that work great and durable. See a file attached with power supply requirement based on usage for your reference.

Good Luck.

Electrophoretic conditions are characterized by the electrical parameters (current, voltage, power), and factors such as ionic strength, pH value, viscosity, pore size, etc., which describe the medium in which the particles are moving.

Current, voltage, and power.

This's an interesting question and the following links provide some useful information in this case. Please compare the content of each power supply brand to find the best one for your lab.

https://www.atto.co.jp/eng/technical_info/electrophoresis/powersupply_electrophoresis_blotting

https://www.biocompare.com/Nucleic-Acid-Electrophoresis/21725-Power-Supplies/

Buying a power supply for electrophoresis depends on your usage. For example, if several users in the lab run many gels in any given time, you may want to buy high current power supply unit. If the use is minimal you may buy a basic power supply. A good choice would be a universal power supply that could be customized based on your requirement. Bio-Rad and Hoefer both offer great power supply that work great and durable. See a file attached with power supply requirement based on usage for your reference.

Good Luck.

Gabriel Rojas Abrahantes

Except people have mentioned, warranty and after-sales-service are also important. For example, if the device beak down, is repair free (for a certain period), discount? Only pay parts cost?

Electrophoretic conditions are characterized by the electrical parameters (current, voltage, power), and factors such as ionic strength, pH value, viscosity, pore size, etc., which describe the medium in which the particles are moving.

In my view, buy the simplest instrument that will do the job. If you're just doing agarose gel electrophoresis, you'll never need to go up to more than 240V. If you're doing acrylamide gels, you may need twice or four times that power.

Power supplies are very simple devices and they last forever. Some of mine are nearly 40 years old and still going strong. For this reason, stay clear of fancy electronics, touch screens and LCD displays. Buy something with a metal casing, bakelite dials and an old-style LED display, and it will serve you forever. Buy something with top-modern electronics, and in ten years' time you will have a fully functional power supply that you can't use because the controls have fallen to pieces. Consider buying a used or reconditioned instrument. Most molecular biology labs are doing much less electrophoresis than they did 20 years ago, so there are a lot of power supplies lying around doing nothing.

Another thing to think about is that you may want to more than one at the same time - e.g. if one person is doing agarose gels and another is doing protein electrophoresis. So two cheap units are better than one expensive one.

Absolutely agree with Andrew Jenkins

Unless you're planning on doing something really out of the ordinary and only want to run few gels there and there get a simple and cheap power supply.

We also have instruments tens of years old and never had a problem with them.

The simpler it will be, the less likely will it break.

They are described as max voltage. If you only run agarose gels and SDS PAGE you will be covered with lovest power available. If you run multiple gels (more than 4) at once or native separation you need to go higher. If you do 2D gels go for max available.

In addition to the good information that others have provided I do like the option for a built in timer. Tends to not be on the very basic models but for me it's a valuable option. At times I'll be in another lab or not in the building but with the timer I can rest assured I won't run the products too long.

Thanks everyone for the help, it has been very helpful.

I agree with dr Rehab A.H. Al-bakr

That depends on the methods you use (agarose, PAGE, IEF), and the size of your gels (mini-gels, 20x20 cm,...). If you never plan to use IEF, then 200 V is sufficient, the current depends on the number and size of the gels you run. 500 mA or 1 A should do the job.

I find a small 40 V, 1 A power supply useful for western blots, they are cheap and free the more expensive high voltage units for actually doing electrophoresis. You get them from electronics supply stores.

For IEF I prefer the specialised units available from several manufacturers (GE, Biorad,...). They work with gel strips with immobilised pH-gradients. Not exactly inexpensive, but compared with tube gels they save a lot of hassle and are more reproducible.

Others have already mentioned the KISS principle (keep it simple, stupid). If it ain't there, it can't break. A simple unit with discrete electronics can be repaired even after 20 years by any competent electrician, for a high-fangled system with integrated circuits you may not be able to get spares after 5. And of course, with high voltage (DC, in combination with high-conductivity buffers!) safety is an issue, the equipment (as a minimum) needs to meet the safety rules of your country.

You also should ask for circuit diagrams and other documentation, especially if you live in a country where visits from a manufacturer's repair specialist is difficult to arrange or where sending instruments to the manufacturer takes unduly long. That helps your craft shop people in case something breaks.

Gabriel Rojas Abrahantes

Bio Rad is the best one.

Moreover, you can discuss with your supplier as what are your requirements and also find out extra feature you may get benefited out of.