#1 Science Forum For Lab Technicians

Hi everyone!

We have just this afternoon become the proud owners of a ex food tech microwave for the Prep Room!

By coincidence I have some exposed agar plates I'd like to 'nuke'. Can someone please tell me how long we should cook them for?

Many thanks

I don't know how long, but I can tell you this... DON'T forget the oven bag!!!

Sassi

OH please sassi, tell us you didn't forget. yuck

Me??? Never....


Sass

I usually do about 15 minutes.

Wendy

Thanks, Wendy!

Hi Liz, It does depend on the watts of the microwave. But as long as they are a nice solid mass, in OVEN BAGS, thats fine. Nothing else will grow. My old one takes about 25 mins. I do this in different stages. 15 mins then 10 mins.

Thanks Sue - mucfh appreciated.

I want a microwave!

Do you think the staff would mind if I used the one in the staff room?????

Yes i would. But if you say to the head teacher, I think the staff should have a new microwave, and you have the old one. Or put a piece in the staff news letter, some one some where may be throwing one out.

When did microwaving plates become and acceptable practice to kill the yukkies?

Last time i chcecked (admit it was 5 years back) it was still considered that microwaving did not kill off everything thus was not acceptable as a method of sterilaization

I'm with you Annette, I don't think the microwave kills the bugs. I bought a new pressure cooker when I came here and it has all the safety features you could want, was not expensive and does a good job (I use oven bags to make the clean up easier). My microwaves at home keep breaking down in less than a year and they are not the cheapies either!
Regards
Sue G

Yes it is debatable. But a lot of new mum put the bottles etc in the microwave. Their is even kits sold to sterilize babies items. On microwaving the agar plates, into one solid mass, how on earth can any thing ever grow??????????? The agar is just a crusty mass.

Hi all

I also love the microwave for preparing agar, but don't go so well at 'nuking' the plates after use. How do you stop the oven bags from exploding!!!! On high power they blow up, but on low power it doesn't boil. I use two oven bags but still manage to have a disgusting mess if I don't watch and stop the microwave on time. Help!.

When you cook or heat up or even defrost in a microwave you generally always have a hole/ vent inthe bag or container so steam can escape donthave it and you get explosion - will be the same for the plates and the oven bag - another reason i can not see microwaving being a safe method of sterilization

Snoopy, the same thing happened to me! What a disgusting mess! I have a very old microwave that only has "reheat" and "defrost" settings. I think someone mentioned earlier to use a low setting, which must be between my two settings.

Are oven bags really ok to use in a pressure cooker?

Robbie

When you use a microwave at home you vent the bag/container so "explosions" do not take place by allowing the steam to escape - would be the same thing.
BUt you shoudl not vent the bags if youa re using them to sterilse bacterial plates - thus why i dont agree with personally using a microwave...but that is personal

Ive also experienced the exploding oven bag senario I now place the agar plates in an oven bag then place the oven bag in an old icecream container marked for this purpose only!!I then "nuke" for 5 mins on high, allow to cool alittle then repeat this process another two times. The mess is then neatly contained for disposal. Interestingly my microwave then instructs me to "enjoy my meal" Maria

FOOD FOR THOUGHT!!!
It would concern me greatly if I had exploding oven bags in the microwave and NOT because of the mess. You should be very concerned about aerosols. That is the bacteria in the air that you could breathe in and make you very sick. I would be avoiding this at all costs.

And YES the oven Bags work very well in the pressure cooker. The temperature of the pressure cooker is 121deg C for 15-20 mins and they cope really well with this.

Lorrae