# What are you using for flask-vent filters?



## gore42 (Apr 10, 2007)

For my erlenmeyer flasks, I'm still using cotton and foil, but for my plastic flasks, that's not really an option. When I ordered some media from the OSB last year, they suggested the use of Nexcare Active Foam 3M bandages (the little round ones), which are autoclaveable and are supposed to do a good job. I gave them a try, but found that on my PP flasks, they would sometimes get moist and slide around during sterilization (and slide off of the vent hole).

I also have had a slightly higher rate of contamination with those flasks than my standard glass flasks, though they are treated the same, otherwise.

So, with my most recent order from Phytotech, I ordered some 3M micropore tape. Honestly, it just looks too thin. Maybe that's just me... but I'd only feel comfortable with the stuff if I had at least two or three layers of it over my vent 

I notice that on some of the plasic flasks that I buy from other vendors (Chuck Acker, for example), there is a thin piece of material under the micropore tape covering the hole. What is that stuff? Feels a bit like teflon pipe-thread tape.

Of course the flasking patches that are available from Tissue Quick are supposed to be good, but they are not very cost effective.

What do the rest of you use?

Thanks!

- Matt


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## Kyle (Apr 10, 2007)

Hi Matt,

Ecuagenera uses the 3M tape, 3 layers thick. They do a high volume of flasks with a normal contamination rate. They replace it when reusing the lids.

I had never heard that about the bandaids, I'll have to look out for that if I ever use them.

Another option is to buy plastic 'culture vessels' from Phytotechnology with vents built in. They are expensive, 20 for $27. Heres a picture:







Now a question for you: I found some large 1 inch test tubes with one hole stoppers to start my phal stem props in. All the information I have tells me to plug the hole with *non absorbant cotton*. Where do I find non absorbant cotton, or does it really matter? I've looked and have been unable to find it. 
Any suggestions on where to find it or on alternatives to plug the stopper with are welcome.


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## littlefrog (Apr 10, 2007)

I seem to recall that years ago it was recommended you use non-absorbant cotton with a drop of concentrated copper sulfate... I could be making that up, it doesn't sound right.

I'd be interested in hearing about more flask venting options, as I'm starting my lab back up very soon (next month, I hope). I haven't flasked since graduate school. Matt, since you use erlenmyers, where do you get them? Sounds like an expensive option. I was thinking about pint/quart mason jars with a drilled lid and something to cover the hole. The plastic containers just don't look right to me, although I've used them before and they work well.


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## Kyle (Apr 10, 2007)

littlefrog said:


> I seem to recall that years ago it was recommended you use non-absorbant cotton with a drop of concentrated copper sulfate... I could be making that up, it doesn't sound right.
> 
> I'd be interested in hearing about more flask venting options, as I'm starting my lab back up very soon (next month, I hope). I haven't flasked since graduate school. Matt, since you use erlenmyers, where do you get them? Sounds like an expensive option. I was thinking about pint/quart mason jars with a drilled lid and something to cover the hole. The plastic containers just don't look right to me, although I've used them before and they work well.



The big question for me is *where do you get non absorbant cotton?*

As for vessels, have you thought of baby food jars? You should be going through lots of them soon, if your not already. They don't hold many plants, maybe 10, but they are cheap and the magenta caps work well.

Kyle


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## littlefrog (Apr 10, 2007)

Kyle said:


> The big question for me is *where do you get non absorbant cotton?*
> 
> As for vessels, have you thought of baby food jars? You should be going through lots of them soon, if your not already. They don't hold many plants, maybe 10, but they are cheap and the magenta caps work well.
> 
> Kyle



Ebay? I don't know how important the absorbancy is, really. I can't see where it would matter, especially if you had copper sulfate in it to keep fungal growth away.

Baby food jars I got... I just prefer to use larger containers. Maybe for mother flasks they would work.


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## Kyle (Apr 10, 2007)

Nope no luck on Ebay. I will use normal cotton balls with a drop of Kocide on the cotton. Or maybe some of the 3m Micropore tape over the stopper hole.

Thanks
Kyle


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## gonewild (Apr 10, 2007)

Kyle said:


> The big question for me is *where do you get non absorbant cotton?*
> 
> Kyle



http://www2.mailordercentral.com/fungi/prodinfo.asp?number=NAC100


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## Marco (Apr 10, 2007)

I copied this from http://personalpages.bellsouth.net/f/o/fourmick/flasks/qanda.html

"Using and buying Erlenmeyer glass flasks and rubber stoppers is killing our hobby flasking budget. What alternatives are available? Tommy and Timmy F., Ray Michigan

A. I strongly recommend against going "plastic"… most of the plastic containers on the market are junk including the popular 4x4x4 boxes. I have had very good success with easy-to-find old Gatorade glass bottles, 32oz apple cider bottles, and large big-mouth clear glass beer bottles with twist off aluminum caps. I'll leave it to your imagination to figure out where to find these bottles… but I'll get behind the store of a $7 to $11 dollar wager that you readers already know. Be absolutely sure there are no dents in the metal cap and drill the smallest possible hole in the middle of the cap. Place a 1" diameter round Nexcare (by 3M) Active Strip spot bandage on both sides of the cap… use no other brand of bandage, I have tried them all and only the 3M active strip will work. These bandages are also perfect for the knuckles of NFL football players… one bandage will last the entire season. These spot bandages hold up in the pressure cooker just fine. Chlorine will eat up the Gatorade caps the third or fourth run through the sterilizing bath."


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## Kyle (Apr 10, 2007)

Thanks Lance,

I haven't been to that site in years.

Kyle


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## Hien (Apr 10, 2007)

Kyle said:


> Thanks Lance,
> 
> I haven't been to that site in years.
> 
> Kyle


 Kyle, The 3M round bandages last thru the whole year without any contamination in the Peruflora pk flask (I did leave the flasks in their little clear plastic sandwich bags as per Greenthings & your suggestion, I believe that helps keep it clean)


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## DavidH (Apr 10, 2007)

Aaron Hicks at the Orchid Seedbank Project uses the nexcare bandages on his flasks. Fred Clarke of Sunset Valley Orchids uses a filter from Sigma labs that looks similar to the nexcare bandage but has better micron filtration. I don't remember the nomemclature, but I can look it up. Fred also uses Mason jars for all his flasking and he doesn't need to replace the filter everytime. I've seen his lab and saw over 200 flasks without any contamination. His quart jars hold a lot of seedlings when he replates. For the money, I think the mason jars are the best. I'm using the small pint jars for my mother flasks and the quart jars for replates. Fred makes a batch of orchid medium and seals the container with a solid top to maintain the moisture level of the medium. He has a second set of sterilized, filtered tops he uses to replace the solid top when he sows seed or replates.


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## gore42 (Apr 10, 2007)

Kyle,

I got some non-absorbent cotton at a local medical supply store, which also has useful equipment for the flasking lab, but not the greatest prices.

I actually haven't bought any Erlenmeyer flasks especially for the purpose of the flasking; I had about 50 empty flasks from flask orders from Taiwan and Ken's Orchid Studio and other places, that I've just collected over the past few years, and I've been re-using them. I have been buying the plastic flasks from Phytotech (not vented; guess I should have looked more closely at their catalog), but their prices for plastic flasks is way too high, so I'm considering buying a wholesale order from the manufacturer, and selling off the ones that I don't need. 

I actually prefer the plastic flasks over the glass... they are easier to de-flask the plants without damaging them (or wasting the money breaking the glass flasks), and they offer more head-room for the plants to grow. 

Anyway, I'm glad to hear that I wasn't too far off with regard to the layering of the 3M tape. I guess I'll try it like that; with three layers or so, and see how it works. If anyone else has other ideas, please let me know!

Thanks!

Matthew Gore


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## gore42 (Apr 10, 2007)

David,

I'll take a look at Sigma's website; that's a good idea, thanks  I use the little pint canning jars for mother flasks, too. They're a great shape for it, and they're cheap, and they seal reliably 

- Matt


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## gonewild (Apr 10, 2007)

Orchids of Los Osos has a surplus of glass erlenmeyer flasks. I checked and they are willing to sell them. If anybody is interested in buying some slightly used, good as new glass flasks let me know and I will quote a good price.


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## littlefrog (Apr 10, 2007)

I'd be interested if the price was right, Lance.

Rob


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## gonewild (Apr 11, 2007)

littlefrog said:


> I'd be interested if the price was right, Lance.
> 
> Rob




How does $2.50 sound?


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## DavidH (Apr 12, 2007)

The filter is a sun cap closure S5939 at Sigma Aldrich. Below is cut and paste from the website. It comes in a roll of 500 sheets for $72.60, but they are reusable.

Sun cap closures 
Biofilter, O.D. 18 mm 

General description 
8 mm 0.02 μm polypropylene filter disc with heatproof adhesive.


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## gore42 (Apr 12, 2007)

Hmm. If those Sigma closures work better than others, it would certainly be worth it, but I wonder how much better they are. Quick comparison:

@ 65 pence per AMD patch ------------- 1 flask = $ 1.30 (approx) for vent from Tissue Quick Plant labs

@ $4.83 for 100 spots ------------------ 1 flask = $0.0483 with Nexcare 3M bandage

@ $72.60 for 500 vents ---------------- 1 flask = $0.1452 with sun cap closure

@ $0.96 for 1" x 10 yard roll 3M tape ---- 1 flask = $0.008 (triple layer, 1" square pieces)

I experimented today with the micropore tape, and it looks as though it stayed where it was supposed to during the sterilization process. I'll probably stick my test flasks in with my orchids for a week or two to see what kind of cultures begin to grow, if any. Don't know if I'll make 500 flasks this year, so $74 bucks seems like a bit much to spend, but I'd like to be a little more confident in the performance of my vents, so it might be worth it.

- Matt


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## Kyle (Apr 12, 2007)

I dont' know about Sigma in the USA, but in Canada it was really difficult to convince them to sell to me, me being a hobbiest. Eventually I was able to jump through all there hoops but not before I had bought what I wanted from the USA. They probably hate me since I went through all the trouble to set up an account and never bought anything.

Matt since you are a buisness, you probably won't have any trouble setting up an account.

Kyle


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## DavidH (Apr 12, 2007)

Actually, from experience with Sigma, they gave me a hard time because I tried to use my LLC for the purchase. Talking to others who recommended them, they said it's best to be an individual person versus a commercial entity. It's one of the main reasons I switched to Phyto-tech.

With respect to filtration, what's the micron filtration level of the nexcare bandages?


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## Chuck (Apr 13, 2007)

Rob,

You mentioned mason jars. I have used them with some good results. I replace the flat metal top with a sheet of transparent oven bag ( the kind used to cook meat in the oven to retain moisture). I cut a hole in that sheet with a hole punch and covered it with a layer of Johnson and Johnson cloth medical tape. I found that the flasks dry out too quickly with a single layer so I use a double layer of tape. My contamination rates are very low about the same as with other glass flasks.

Chuck


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## littlefrog (Apr 13, 2007)

Chuck said:


> Rob,
> 
> You mentioned mason jars. I have used them with some good results. I replace the flat metal top with a sheet of transparent oven bag ( the kind used to cook meat in the oven to retain moisture). I cut a hole in that sheet with a hole punch and covered it with a layer of Johnson and Johnson cloth medical tape. I found that the flasks dry out too quickly with a single layer so I use a double layer of tape. My contamination rates are very low about the same as with other glass flasks.
> 
> Chuck



Do you autoclave (/pressure cook/) them with the oven bag and tape on? 

Rob


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## gore42 (Apr 13, 2007)

More experimenting yesterday....

I've found that using the 3M bandages with a strip of micropore tape over the top keeps them from sliding around when they're heated, which was the only significant problem I was having with them.

I guess that some people are using the bandages on the inside and on the outside of the vent hole, which I also haven't been doing. I'll do that in the future to reduce the risk of contamination, I guess. With this method, I'd be looking at about 11 cents per flask on venting materials, which is manageable 

- Matt

David, I haven't been able to find a filtration level for the Nexcare products. Maybe and email to 3M would get the answer, though...


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## Chuck (Apr 13, 2007)

Rob,

Yes I do. I use a pressure cooker. The above mentioned materials do fine in it. 

Chuck


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## British Bulldog (Aug 14, 2007)

*Non absorbant cotton wool!!*

Dear Kyle,
Sigma has it here in the UK.
Ask??
Paul


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## Kyle (Aug 14, 2007)

Thanks Paul,

I will check with Sigma in Canada. But it won't do me much good since they refuse to sell to me since I am a hobbiest, not a business. I Have been using fabric tape with good success and am going to move away from closure devices that require cotton.

Thanks!

Kyle


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