2-5 μL

As for me,

If you used a pre-mixed master mix i.e., ('Coloured ones') you just do the direct loading after also having pre-stained the gel during preparation. I would suggest 5μl to 6μl of the sample.

If you are to use a loading dye you can add 1-2μl of loading dye and 4-5μl of the sample to make a total volume of 6μl.

Hi Karen Nohemí Benalcázar Andrango

It really depends on the visualization agent that you are using. Most commonly used dyes like GelRed, SYBR Safe etc. can detect as low as 50ng on gel.

I would suggest to load (5uL PCR product + 1uL 6X loading dye).

Subham.

While agreeing with the above answers, one other aspect is the yield of particular PCR product that depends on a number of different factors, including the primers set used, starting template concentrations, size of the PCR product, cycling conditions, cycle numbers, etc. There is one other aspect also, and that is, is this PCR analytical or preparative? For analytical/diagnostic purposes, you may go in with higher volumes/concentrations on the gel, since you just really want to check the presence of a specific PCR product. On the preparative PCR, you want to go in with the lower volumes, so as to use the rest of the product for your downstream applications. Even in this scenario, you may perform first an analytical PCR to work out the optimum conditions, before you proceed with your preparative PCR for downstream work.

5 µL

5_8μL

2-4 ul is good enough.