How to prepare a 3.5% agarose gel ?

[itamo]

I tried a prepare a 3.5% agarose gel for electrophoresis, i tried to cook it on a hot plate with a rotating magnet, but there were alot of bubbles in the gel.

Is there a way to prepare a high concentration gel without the annoying bubbles?

[JackBean]

quickly heat in microwave for short periods of time with mixing in between

[itamo]

Thanks.

Do you cover the flask to avoid evaporation ?
If you do, with what ?
Did you tried it yourself?
How many cycles of heating and swirling did you do?

[JackBean]

I usually do it in the bottle with cap and I keep it on (just not tighten it firmly). As long as it is not properly dissolved.
I'm usually working with 1% agarose, but I think I have prepared also 4% in this way.

[itamo]

I cooked it on a hot plate on low temp with a stirring magnet and in the end put it in a microwave oven on low-medium for a couple of soconds a few times to get rid of the bubbles. and after getting a clear solution i added the atidium bromide.
worked great.