Preparation of agar medium for flasking

[Afid]

Yes, I haven't checked on it in a while but it has not gelled hardly at all, I was wondering if maybe the pressure cooker had diluted it and that seems like the most likely explanation but I have heard of people using pressure cookers for it before with no issues. I was following the instructions linked on the packet here http://orchidseed.com/OSPmediapreparation.pdf and getting extra info (because of the lack of detail in those instructions) from here: https://www.atzlabs.com/prodcut-info...dSowingKit.pdf

---------- Post added at 10:12 PM ---------- Previous post was at 10:02 PM ----------

Update: I just checked on them and one of the two I did last (because when I did them first they tipped over) is partially gelled but not very much. I also noticed that there was considerably more liquid in the jars. I think I will try putting way less water in the pressure cooker so that it can't splash up into the jars. Or using something to elevate the jars above the water (which I have heard suggested before).

[neophyte]

Afid - what kind of jars are you using? Is it possible to cover them with something to allow air flow (so things don't explode) during the heat treatment while keeping water out (ie. some sort of impermanent cover that's not completely sealable but still prevents water from getting in)? I searched up something along the lines of "using a pressure cooker as an autoclave"/"using a pressure cooker for sterilization" and most of the pictures show a jar with an aluminum foil cover wrapped around the neck of the flask/jar. Afterwards the sterilization process you would obviously completely seal it.

[Afid]

Ah, maybe foil was the crucial step I missed, I am using mason jars currently, but I could also use plastic containers. I bought them for the purpose of flasking (I have like 200 of them) but they almost certainly would melt so I would have to sterilize them another way.

---------- Post added at 10:33 PM ---------- Previous post was at 10:32 PM ----------

I had the lids set on top of the jar but offset so that it wouldn't form a seal.

[neophyte]

ps: agar tends to foam when it's heated. I've only heated agar a couple times ever but that's just my experience. not sure if this makes a difference?

[Afid]

I have encountered the foaming tendency of agar in the past (during a previous flasking attempt that was in hindsight never going to work). But I think the high pressure inhibits the formation of foam pretty well.

[neophyte]

there is another sterilization method that has been discusssed on the forum which doesn't involve pressure cooking – it uses the chlorine that household bleach releases to kill bacteria. the infection rate is kind of high but it seems to work for multiple people. here is a link: Very Easy Sterilisation Method - My Seedlings (some of the pictures are missing but the instructions are intact)

I'm sure you can figure out the pressure cooker method but I'm just putting this out there... maybe you could compare both methods.

[Afid]

Yeah, I have been thinking about trying a few different techniques and figuring out which works best for me. Luckily I still have 400ml or so of extra media left so I can try a few more times. Although I will likely have to order more soon anyway.

[neophyte]

Where are you getting your medium from? I'm not sure my parents would let me buy it (they've decided my orchid obsession has reached unhealthy levels) but I'm just curious.

[Afid]

I got it on ebay, it is pretty cheap actually. here is a link to the seller https://www.ebay.com/usr/ajorchids?_...p2047675.l2559

[neophyte]

wow, thanks for the link!!