Darklight Posted May 19, 2012 (edited) I've been promising this one for ages, but haven't been able to find the specs. Mine was er... borrowed. Ten years ago. And not returned. Hint hint... Perspex tunnels are brilliant! You can get them made really cheaply, and they last forever. As long as they're not borrowed. What they do is give you a chance to start plant tissue culture or sterile myco work *really* cheaply. They pack up small. And if you're ever culturing on the move you can set up in a bathroom or motel room- anywhere you can reduce air flow and wipe down the surfaces around you They're *great* to start off plant tissue culture or sterile myco work with- gives you a chance to refine your technique and see if you like the craft of it before you invest big bucks and square home meterage with a glove box or flow cabinet. I started out in one, and managed about 100 @ 30ml tubes a day ( about 1L media ) for a couple of years til I got the chance to purchase a flow hood. By then I knew I was serious. The one in the pics isn't mine ( and I'd better return it ). It's a little different. Personally I prefer a single piece of perspex in my tunnel- this one pictured interlocks two pieces for easier transport and storage, which potentially could compromise sterility. As you can see in the pics this one doesn't seal really well where the two halves connect. But you get the drift It's basically a U shaped piece of perspex with open sides. You saturate a couple of pieces of paper towel with 70% ethanol ( or metho ), place them on a flat surface in a clean room with minimal airflow. Away from this, you saturate the unit both sides with 70% metho, wipe it with a paper towel wet with same, and put it on the paper towel. Anything which could be knocked over or burned should be safely away, as it is also a contamination hazard. A dedicated folding table in a bathroom with a closed door is optimal. A kitchen table shared with the family and a gazillion plates is a menace to everyone including your work Anything that goes in the tunnel- culture tubes, petri dishes, your gloved hands, unopened scalpel blade packs- should be sterilised with 70% metho and again *each time* after you remove it/ them. Culture tubes should be opened, worked and closed on a slight slant to allow for better access and to minimise contamination. Close all sterile vessels before you remove them from the tunnel Once anything leaves it you can consider it compromised re. sterility. To sterilise scalpels and forceps between uses, have a 200ml beaker of 100% ethanol ( or metho ) almost full nearby, dibble the sharp ends to remove any debris, and flame sterilise carefully- as you normally would. I emphasise carefully. And don't panic if you set fire to anything, for Christ's sake don't knock that beaker over. Metho fires are low temp and you have time not to panic as long as you set up carefully and properly in the first place Below are some approximate dimensions- you might want it larger if you have large arms and hands- but not too much larger. You don't want the unit too tall- if you have too much air around your sterilised arms and gloves it could move in and contaminate your work. You don't want the unit too long or it'll be unwieldy to work in. You want back and front 'legs' slightly sloping and you want the top to slope down towards you so you get minimal glare off light sources. Recommended dimensions are: Height at the back: 160mm Height at the front: 125mm Length: 300mm Width at the bottom ( open section ) 210mm Width at the top ( closed section ) 170mm Yes, they are a bit fiddly to work in. They'll perfect your culture technique no end. They're not fast, or for bulk work. But contamination wise they are as efficient as a flow hood if your setup and technique are good. What's the point of spending a kay or more on a flow hood if you don't have good technique? Why blow the cash if you aren't sure you're going to stick with it? When you're finished, wipe it down with more 70% metho and store in a box or some way it won't get scratched between uses Any questions ask away Edited May 19, 2012 by Darklight 1 Share this post Link to post Share on other sites
planthelper Posted May 20, 2012 very simple, and simple is often very good, specialy when one wants to start of a tissue culture project. im amazed to see that it has no bottom and neither sealed ends. no bottom is ok, and can be used to advantage, but totaly open ends? maybe my idea is overkill, but one could easely close off both ends with plexi but with a hole which, fits your gloves. i might diy something like that, nice inspiration. obviously it serves you realy well, great post. Share this post Link to post Share on other sites
Darklight Posted May 20, 2012 im amazed to see that it has no bottom and neither sealed ends. no bottom is ok, and can be used to advantage, but totaly open ends? Yeah seems too simple to be true, if I hadn't started using them in my tissue culture class at TAFE 25 years ago I wouldn't have believed they worked. But they do OK the bottom is open- because you're resting it on 70% ethanol soaked paper towels ( any contams which land there stay there and die ) The sides are open- technically- but in practice they are filled up mostly by your hands and wrists, which are sterilised by spraying 70% ethanol on them. Your hands and wrists actually block a lot of the air going into them, and careful work while they're in there pays off It's not something you leave lying idle, you're working in it, sterilising it or it's packed away Ah- and don't autoclave or pressure cook them. Perspex doesn't like it. 70% ethano or 70% metho is *fine* Glad you like it pH Thinking about running a workshop on them at a conference sometime Share this post Link to post Share on other sites
kadakuda Posted May 20, 2012 very cool. im making a hood for home, but have been wanting something like this for travel. will make one for our next trip to fit into our pack. so simple, yet a pretty good idea. im invisioning a small one with open bottom and use papertowl like you say, but keep the ends small and clsoed off with large rubber gloves for even less air flow. Share this post Link to post Share on other sites
Darklight Posted May 20, 2012 (edited) It could work, but do keep in mind that any surface area, complexity and seals you add to the area all add surfaces you need to sterilise and keep sterilised while working. Seals will break down over time and add places for contam to hide. Especially if they're not formed smooth in the first place Gloves and closed ends will add a lot of surface area, and if you add two, the only way you can get stuff in is to lift the tunnel, which will require a re-sterilisation I do tend to err on the side of caution when changing these things- the potential for extra contamination is only potential, and your technique could well ameliorate they risks Edited May 20, 2012 by Darklight Share this post Link to post Share on other sites
