Microwave experiment #1

I have heard a lot of wishy washy "facts" about sterilizing media in the microwave, so I organized a test to see if it really is possible for this aspect of flasking to be greatly simplified...
I went to my local grocery store and bought 8 of each of the following:
GLAD food containers, the smallest available.
Rubbermaid Food containers, Also the smallest size.
And Rubbermaid "stain proof" food containers.

I first added a bit of medium to the glad flasks, and microwaved them for one minute. The result was the lid popping off for ventilation of steam...
I then tried some Glad flasks with the lid slightly ajar, then after microwaving for one minute, carefully pushed the lids down to seal them. I found this works best if you wait till the media cools slightly so the container wont implode on you.
Next I tried the two rubbermaid flasks in the same fashion but only nuking for 45 seconds... these also had the problem of lids staying on, so I reconfigured the angles... I vented four of each flask with a hot wire poker to make a hole, and a bandaid brand "clear spot" to cover the hole, taking time to thoroughly brandish the adhesive down. These flasks were then tightly sealed and nuked for 45 secs.

The results:
These flasks were done about eight or nine days ago.
The Glad containers had about 50-60 per cent contamination.
These flasks were unventable due to the Glad logo embossed on the lids, and the media bubbles too high during nuking to vent the side...
Both rubbermaid containers without vents incurred about 25 per cent contamination...
Where as the two rubbermaid vented flasks had zero contamination!!
I also nuked eight pyrex test tubes with media, and an ordinary cotton ball stuffed in the end, then, when done nuking, applied a rubber stopper, also with zero per cent contamination.
So far, there is no evidence to convince me that microwaving is an unsuitable way to sterilize media. I might also add that the rubbermaid stain proof containers are made of durable polycarbonate and are crystal clear, the clearest I have found yet. To further this expariment I want to see if it possible to leave protocorms in the mother flask longer if it is vented for gasious exchange and allows plenty of light in.. I always have a problem rationing corms into replate flasks. Maybe this way they can grow bigger before replating is necessary. I did once grow a flask of epidendrums completely in an unvented mother flask-mason jar, from seed to compot in only one flask, in only one year, and havent lost one seedling yet to this day. I'll let you all know how that one turns out!

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Drew

Interesting test, Drew. Thanks for sharing your results.

One thought to consider...

While I can't believe microwaving would be all that healthy for humans, do we know that it kills bacteria? Those contaminated flasks could now contain some exotically muntant life forms in that rich, nourishing media. You could be flasking the future grex: Godzilla x Mothra. Be sure to post pictures when the critters mature! Oh, and good luck feeding the little beasties. Hope you don't have pets...

Julie

Hi Drew,

Thanks for the info. I've got a couple of Paph Lebadyanum pods so I'm starting to think about this sort of thing and it's good to know that I can maybe use this set up.

I guess the next step is, how to then pop in the little seeds into the sterilized media and still ensure no contamination... maybe this is where I have to do the boiling water and do my flasking in the steam area.

cheers
tim

Tim,

You bring up an interesting point, I have been thinking of a different way to innoculate the flasks with seed without having to open the lids in a flasking chamber, flow hood, or over steam ( which hasn't worked well for me). My Idea is to sterilize dry seed as per traditional flasking i.e with bleach dilution or hydro peroxide... But what I intend to try is little different. I want to try and sterilize seed inside a sterile syringe, rinsing with sterilized water and decanting it off through a filter so as not to lose the seeds. Then switching the syringe to a sterilized needle and injecting the flask through some sort membrane or rubber filament. Or perhaps, just through the side of the flask if using one of the more flexible brands, then immediately patching the needle hole. I need more viable seeds for this experiment and I will get back to you when I have results.

Oh and Piper,
I thought of that too, that the microwaves might not be really killing the micro-organisms, so I took agar medium from a pre contaminated flask I've had on my shelf for a year (very fuzzy by now) and nuked it in the vented rubbermaid flasks. Dead as doornail.

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Drew

Phew! Good news, Drew! I'll sleep better tonight...

Julie

When I saw Pipers name along with the word Microwave ... I just had to look lolol . Good info. Drew.

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Never put off until tomorrow what you can avoid all together.

Yeah, Gin...

I've been back to the nuker with my 'chids again. Put a stray cat in with my most recent dend and got me a three-legged one with a tail and fragrant blooms. It's a bit weird because it coughs up hairballs when I water it, but hey - scientific progress!

I'm just lovin' my microwave. That an' the Superthrive are openin' this orchid world way wide up!

Julie

Cat?? Hmm don't be surprised of the ASPCA shows up at your place with a search warrant!!

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Diane

"NA BEAN DO'N CHAT GUN LAMHAINN"

Sheeeeee's baaaaack!

Oh man, Diane - you're back on-line! You down under yet? I'll have to duck back quick and edit those other posts I made. I thought you were AWOL for a few more days...

oops!

Julie