Flask Sterilization

[Shado]

Hey Hey!

So my Seedpod might be ready any day and i need to make some flasks with medium.

I have some problems with sterlize them. :c

I know you can use a pressure cooker/autoclave to get it to 125 °C or something like that. But i do not really want to spend the money on one and im a lil bit scared of them.

There is the debatable microwave option wich as i read works but doesnt. So i dont think i can make that work with my microwave. x.x

So i catched up a method with steaming it in a wok like chinese buns but i doubt it will reach 125°C in there. And i dont find the source anymore sadly.

A normal waterbath like with jams wont work either probably. :/

I dont really have any fancy chemical fumes to serilize either (just H2O2 12% and Isoprop 90%)

sooooooo im out of ideas what to do really. Is there any method you guys know for low budget and a relatvely high succes rate (low conatmination rate)? :3

Thank youuuu~

[Roberta]

I will leave it to members who do flasking to advise on what might work for you. But as far as temperature is concerned, the maximum temperature that can be achieved with boiling water at atmospheric pressure is 100 deg C at sea level, lower at elevations above that. To get higher temperatures you have to be able to raise the pressure (which is where the pressure cooker comes in). You can't get around the laws of physics and chemistry...

[Shado]

Originally Posted by Roberta

You can't get around the laws of physics and chemistry...

I wish i could sometimes tho TT

Well cant i just not heat up the air with an oven? Does it has to be a waterbath?

[Roberta]

You can heat the air in an oven, certainly. I don't know what the extra heat will do to the medium, or where the limits might be. I leave that discussion to people who actually do this.

[estación seca]

You can't heat liquid medium in a hot oven because it will evaporate. Inside an autoclave or pressure cooker the environment is 100% water vapor, and the liquid being sterilized will not evaporate. Powdered media will decompose if heated too high when dry.

Boiling water does not reliably kill fungal nor bacterial spores. The temperature must be higher. So it is useless to sterilizes the dry items in the oven, then add boiled water.

Electric pressure cookers do not get hot enough to sterilize. Only stovetop pressure cookers do.

[Ray]

If you're talking just the glassware, 10% household bleach in water will work fine.

If you're talking plating medium in the glassware, a pressure cooker is the most reliable at-home methodology.

[Dorchid]

You could try the microwave method and add Plant Protective Mix from Plant Cell Technologies and gentimiacin or some other standard antibiotic used in tc. This would give you some protection and might see you through without the need for a pressure cooker (I gather they’re tough to source in Europe). Another method would be chlorine gas sterilization as posted in this sub. Very Easy Sterilisation Method - My Seedlings

For discussion sake, steam is used to sterilize tools, media, etc. as it contains much greater energy than hot air or water due to the principle of latent heat/energy (of vaporization in this case)…it’s not the temperature that is the key, but the energy…look it up for an actual definition but the gist is that steam contains all the energy required to convert the water to steam. When the steam condenses on the load (tools/media), that energy is transferred to it. Anyone ever blasted with steam can attest to what serious damage can result from very minor contact.

[estación seca]

Are stovetop pressure cookers hard to buy in Europe? Kuhn Rikon in Switzerland makes them. At one time a Spanish company called Fagor made them, but I think they are no longer business.

[Shado]

Originally Posted by estación seca

Are stovetop pressure cookers hard to buy in Europe?

Well they are not that much used here. There are some, sure. But since i am a student, my financial options are limited you know. The cheapest one i found that was big enough for the flasks were like around 100€.

They are not really hard to find but very expensive most of the time.

---------- Post added at 12:16 PM ---------- Previous post was at 12:12 PM ----------

Originally Posted by Dorchid

You could try the microwave method and add Plant Protective Mix from Plant Cell Technologies and gentimiacin or some other standard antibiotic used in tc. This would give you some protection and might see you through without the need for a pressure cooker (I gather they’re tough to source in Europe). Another method would be chlorine gas sterilization as posted in this sub. Very Easy Sterilisation Method - My Seedlings

I saw that methods already but they are too complicated to do here. Germany is a little more restrictive with stuff and sewing orchids is not really a big thing here. So resources and lab stuff that you can get as a private person are limited. (also as plant antibiotics)

Originally Posted by Dorchid

For discussion sake, steam is used to sterilize tools, media, etc. as it contains much greater energy than hot air or water due to the principle of latent heat/energy (of vaporization in this case)…it’s not the temperature that is the key, but the energy…look it up for an actual definition but the gist is that steam contains all the energy required to convert the water to steam. When the steam condenses on the load (tools/media), that energy is transferred to it. Anyone ever blasted with steam can attest to what serious damage can result from very minor contact.

Thank you for explaining! I understand now that its not due to the water but the energy itself. Makes a lot of sense actually xD