melting agar without a microwave.. - (Dec/05/2007 )

I've managed to do something a little silly- I mad up my agar in a flask thats too big for the microwave (oops). Its been autoclaved and has now solidified, how do i get it to melt again?
I tried a water bath to no avail....what about an incubator turned up high?

Easiest would be to put it in the autoclave briefly. I hope it has no temperature sensitive additions.

yeah I thought that, but we don't have our own autoclave, and the person who normally does it isnt in. this kind of thing always has a habit of happening when you're in a rush...

Maybe there's someone at your institute with a bigger microwave (well, it depends on how big your flask is...)
I think it may be worth it to check other labs.

If it's a top-agar medium it may work to put it in the waterbath, but I don't see it working for a medium with high agar concentration... I've tried it with LB and it didn't work - obviously it depends on the temperatures your waterbath can stand...

you can try and break up the solid agar in the current flask so you can transfer it to a smaller flask that will fit in the microwave for melting.
I've done that before with agarose to dispose it from a flask, so it should be the same for agar. to keep sterile conditions just do it in a hood, always more fun to work with limited mobility

cheers guys- i managed to melt in an incubator turned up high- though i was considering trying to break it up.
Unfortunatly now im my impatience ive got bubbly plates- but hopefully they'll do
Would you believe there is no one with a bigger microwave?

if it happens again, you can melt the agar in a boiling water bath. that's how we did it before microwave ovens made their way into the lab.

About the bubbly plates: when you're plating media and you get bubbles in it, you can always breefly flame it (I usually do it with the bunsen burner, but a lighter works as well, I believe). This will make the bubbles pop and you'll have bubble-free plates

Do not flame the plates for too long though, you'll burn the medium...

cheers for that. turns out they worked fine, and though the plates are a bit bubbley its quite easy to tell them apart from colonies.
At least I wont be making the same mistake again!

About the bubbly plates: when you're plating media and you get bubbles in it, you can always breefly flame it (I usually do it with the bunsen burner, but a lighter works as well, I believe). This will make the bubbles pop and you'll have bubble-free plates

Do not flame the plates for too long though, you'll burn the medium...