Dewan,

There is no one specific best acrylamide concentration / voltage.   There are just guidelines and rules of thumbs.

Resolution versus Speed

If you're in a hurry or if you have many gels to run in a short amount of time, then you need the gel to go fast.  If it is critical that you get high resolution so that you can clearly distinguish between bands that are close together, then you're going to want to push the DNA or Protein (depending on the type of gel) slowly.

For Higher Resolution

For higher resolution (prettier gels) you want higher concentrations of gels and you you'll want things to move more slowly so you'll go with a lower voltage.

But you have to remember, the higher your gel concentration the more difficult it becomes for the samples to move through the gel.   Also, the larger the fragment size (protein or dna), the more difficulty it has moving through the gel.  So, a large protein (or dna) moving through a high concentration gel moves very slowly.  BUT, you get better RESOLUTION this way.

On the other hand (heavy sigh) if the fragments are very small, then moving them too slowly could give them time to diffuse laterally instead of straight forward.  So, for very small fragments, too low a voltage can be a very bad thing.

For Faster Run Times

If you're short on time, well, then you need the fragments to run through the gel faster.  That's simple.  Use lower concentrations for the gel and crank the voltage up.

SIDE NOTE HERE: Turning the voltage way up means the solution is going to heat up faster.  If you're not careful, the gel can actually start to melt.  So, here's a short cut that I have used and it does work but I can't say it's the best way to go.  IF you need to crank the voltage up but you don't want the system to overheat, Dilute the buffer solution.  (I've diluted normal TSA by half and used it).  Just remember not to reuse the buffer.  Use it once (if diluted) and then pour it out.

Lower gel concentration

Using a lower gel concentration means it is easier for every sized fragment to get through.  You'll save time, but you WILL lose resolution.

Higher Voltages

A higher voltage means a stronger field.  A stronger field means a faster run, but again, you WILL lose some resolution.

The only way to find the exact right gel concentration, voltage, and buffer concentration for the protein or dna you are running, is experience.... Trial and error.

I wish I could give you a specific answer, but you're just going to have to get in there, make your best guess based on what you know, and try... Adjust and try again...  that's research.  

Good luck with it!

Dear Dewan,

I suppose that you are talking about polyacrylamide gels. Voltage and time do not depend on acrylamide %. Use the voltage recommended by the manufacturer of your electrophoresis equipment (it will depend on  the length of the gel and on the efficiency of cooling. Add tracking dye (bromophenol blue) to your samples and stop electrophoresis when the dye reaches the bottom of the gel.

May be you have to consider the size of your protein and the type of gel and buffer you are running your samples. Usually, you can find all the information in guidelines provided by the sellers (Thermo, Abcam). Good luck.

Dewan,

There is no one specific best acrylamide concentration / voltage.   There are just guidelines and rules of thumbs.

Resolution versus Speed

If you're in a hurry or if you have many gels to run in a short amount of time, then you need the gel to go fast.  If it is critical that you get high resolution so that you can clearly distinguish between bands that are close together, then you're going to want to push the DNA or Protein (depending on the type of gel) slowly.

For Higher Resolution

For higher resolution (prettier gels) you want higher concentrations of gels and you you'll want things to move more slowly so you'll go with a lower voltage.

But you have to remember, the higher your gel concentration the more difficult it becomes for the samples to move through the gel.   Also, the larger the fragment size (protein or dna), the more difficulty it has moving through the gel.  So, a large protein (or dna) moving through a high concentration gel moves very slowly.  BUT, you get better RESOLUTION this way.

On the other hand (heavy sigh) if the fragments are very small, then moving them too slowly could give them time to diffuse laterally instead of straight forward.  So, for very small fragments, too low a voltage can be a very bad thing.

For Faster Run Times

If you're short on time, well, then you need the fragments to run through the gel faster.  That's simple.  Use lower concentrations for the gel and crank the voltage up.

SIDE NOTE HERE: Turning the voltage way up means the solution is going to heat up faster.  If you're not careful, the gel can actually start to melt.  So, here's a short cut that I have used and it does work but I can't say it's the best way to go.  IF you need to crank the voltage up but you don't want the system to overheat, Dilute the buffer solution.  (I've diluted normal TSA by half and used it).  Just remember not to reuse the buffer.  Use it once (if diluted) and then pour it out.

Lower gel concentration

Using a lower gel concentration means it is easier for every sized fragment to get through.  You'll save time, but you WILL lose resolution.

Higher Voltages

A higher voltage means a stronger field.  A stronger field means a faster run, but again, you WILL lose some resolution.

The only way to find the exact right gel concentration, voltage, and buffer concentration for the protein or dna you are running, is experience.... Trial and error.

I wish I could give you a specific answer, but you're just going to have to get in there, make your best guess based on what you know, and try... Adjust and try again...  that's research.  

Good luck with it!

Running polyacryalmaide gel at 120V takes about 2 to 2 n half hours for a 10x 10. 5 gel cassette. The voltage of 100 to 120 is generally fine. Increasing the voltage will speed up the running, however the heat generated will not be good for the gel as well as the equipment.