The Orchid Source - Orchid Forum

Hi everyone,

I am considering switching to vented flasks for my replates and was wondering if anyone makes their own and how. I know that it might be easier or convenient to just purchase them from e.g. Phytotech Labs but they are quite expensive, though.
I prefer wide opening flasks rather than the erlenmeyer type which can be sealed with a perforated rubber stopper

Any ideas or input in welcomed, thanks!

I have received flasks that had medicated Band-Aids over the vent holes.

Ditto and they seem to work well. In Japan you can buy porous discs that cover the hole but they are not cheap and you probably have to buy a thousand minimum.

Assuming they are available in Aruba, 3M Nexcare foam band aids work great. The shape I use are called Spots. They are 7/8 inch diameter round.

I would try the band aids too, as that is what I have been hearing is useful on plastic "flasks". But I have very little with flasking.

I make my own vented flasks by punching a small hole in the lid, inserting a small amount of cotton, and covering both sides with Nexcare porous tape on both sides. The tape stays on, and I have no problems with contamination via the vent. I have used Band-Aids in the past, but have to replace them often, and I am not certain of their integrity after one use.

I really like the commercially available venter lids, but at $44 for 25, they are too expensive for the number of replates I make.

Hi y'all,
Thanks for your input! I found the Nexcare round band aids here and am going to give it a try as Brian describes.
Thanks again!

Chris

If the bandaids don't work for you, try these:

http://www.tissuequickplantlabs.com/fppg3c.htm

You can reuse these many times, I cover them with a little micropore tape.

Probably cost more than nexcare bandaids... but work well.

Hey group, a word on Vented flasks.... I am very old school and this is how I do it......I recycle the fruit juice beverage bottles (glass)... the glass Welches GJ bottles work great but Snapple ect will too.
The stopper size for these is a neoprene # 25 or there rubber stopper #25. I buy these bulk with a single hole, but you can drill a 3/16" hole with a drill if need be. That said' this hole is filled solid with cotton or synthetic cotton ball and a few drops of strong iodine antiseptic is dispensed into the plug.
I cover the stopper and media in the bottle with aluminum foil over the top and sterilize in a pressure cooker at 15 lbs for 45 mins. Everything is reusable and cheap too.

That's exactly what I do. But I use the small Enfamil bottles of baby milk and water as mother flasks, so I don't have to use bigger bottles for this.
I noticed that you sterilize for 45 minutes, I do it for 20 minutes and is enough for orchid seed sowing media.

Thanks for your post!

I have one remark, though. To me (a pharmacist) it seems that adding the iodine solution to the cotton wool plug and then sterilizing defeats the antiseptic purpose of the iodine. Whether iodine solution (iodine in ethanol or iodine + iodide in water/ethanol) or povidone iodine is used the molecular iodine present will probably sublimize during the sterilisation process as the temperature during sterlisation in a pressure cooker is usually in the 115-130 Celsius range which is well above the sublimation temperature (phase conversion from solid to gas) of iodine (113 Celsius ). I am just speculating here, but I guess that impregnating the cotton wool after sterilizing would make more sense.

@ Irma:
You are correct: using a common household pressure cooker and the size of the pan, 15-20 minutes of sterilisation time is sufficient to guarantee sterile media. Prolonged sterilsation might adversely affect media compostion (heat degradation of components).

As an update: I've used glass jars of which I punctured the lid, put a small dab of cotton wool in the opening, covered on both sides of the lid with Nexcare tape and sterilized in the presuure cooker. So far, all flasks haven't contracted any contamination.

Hey group! I have seen not a single problem with degradation in the culture medium with these temps in more than 35 years of lab work with hundreds of crosses....sublimation of the iodine....Hmmmmmmm. At the 155F. temp I havent noticed it, as for application of the iodine solution, before or after sterilization, I doubt that it matters. I cover the bottles after sowing with a clear plastic bag anyway to avoid condensation drip and contamination from that too so the use of the iodine is just a guaranee against exterior problems too. I looked at the cost on the stoppers after the post and these are going for about $18.00 a pound (about50 count) and the stoppers don't degrade for many yearshappy Anyhow happy growing....TTFN Tom