"Brick Top" Glovebox Tek
Posted 30 April 2005 - 01:33 PM
The purpose of a glovebox is simple. It is used to create a STILL AIR environment so that you may work without contamination spores flying all over your stuff. I have seen a bunch of "positive pressure" boxes and I dont know about all that. That to me seems to be trying to mimic a flowhood. There is a reason that flow hoods have 6 inch thick hepa filters. I recomend to stay away from such homemade positive pressure boxes and stick the the simplest and cheapest method possible.
A GB also beats a flow hood (and positive pressure box) in a very important task - Working with contaminated cultures. Lets say you are trying to save an isolation on an agar plate with a small contamination, a flowhood will just be blowing all those contam spores all over everything in the work area and you will not be able to escape its iron grasp of doom. What is needed is very still air, so you can cut a chunk and drop it in a fresh plate without getting contam spores from the old plate in the new one. You see what Im talking about.
Enter Brick Top. This ol gal is nothing but a cardboard box lined with black plastic sheeting with armholes and some weatherstripping at the top. She has an oversized plexiglass top that is placed on after the box is loaded up and weighed down with a few bricks. Then a light is placed on top and you have a top notch, easy view GB!
Building Brick Top
First get your supplies ready.
cardboard box (24x18x14)
black plastic sheeting roll
(2) big plastic cups from the gas station
Plexi Glass that is about 4 inches bigger than the top of your box
Roll of weather stripping (3/4" thick foamish kind)
Hot Glue (Gun)
Flourescent light (One from a ten gallon aquarium works fantastic cause it sits flat)
plastic sleeve from petri dishes (or similar plastic tube shape) cut to 10" lenghts
First, cut the top flaps off of your box. Leave about 2" of the flap connected to the box and fold them out so you get a "rim" arround the box on all sides. use an exacto for cutting. make sure its sharp and fresh. Dont cut your hand off. Seriously.
Now is the hardest part. You need to line the inside of the box with plastic sheeting so the cardboard doesnt get wet when you disinfect the box to work. I did this with 3 peices of pastic. 1 for the bottom which was about 4 inches too large on each side so that it formed a "bucket" to collect excess water that drips down the sides. Then 1 that went arround the sides, except the "front" or glove side. This layer needs to go on TOP of the bucket bottom so that run off spray will run into the bucket bottom and not underneath it and the cardboard. It also needs to overlap the top flaps of the box and be folded down so there is no way you are going to be getting any cardboard wet when you are spraying the box. The last peice will cover the front or glove side. it needs to be done the same as the other side piece. You could try to cover all the sides with one sheet, but when your overlapping the top the plastic sheeting will take a odd shape and its just easier to me to bend it in 2 peices instead of one. Make sure there are not many wrinkles in the plastic. Attach the sheeting to the box with hot glue or duct tape (folded over to be double sided). Again try and get it as flat and wrinkle free and tight as possible so it is easy to wipe. This part takes a little patience and dont skimp. You want a high quality device right?
Ok, now that that part is over you should have a box with the inside lined in plastic that overlaps the top flaps. Now, lay on your weather stripping. Do one piece per side. Try and take your time to get them to be flush against each other. I then hot glue the gap (even if there isnt one) where they meet, but only on the side not the top. Put the weather stripping on the flaps you left of the top, on the overlapping plastic. You want the sides to be able to support it so they dont bend down when the plexi glass is put on.
Now, take the big plastic cups from the gas station and cut it about 3" from the top. Dispose of the bottom half. Take one of the tops and draw a template (please do this step dont skimp) where the arm holes will go. For the love of god take your time here. You want to put the arm holes even and straight in the middle of the box. Pretend the holes are there and "dry run" it and see if its comfterble for you with your arms in that position. When you get your arm hole templates where you want them, cut them out. Then cut the plastic sheeting out in the same shape as the arm holes.
Now prepare your "arm holes." Take the cup tops and rubberband (2) the petri sleeves on the outside of the cups at the widest part (top) so the sleeve goes in the same direction as the top would go if it got wider (does that make sense?) You could also hit the sleeve up with some hot glue to make sure the sleeves dont get pulled off the cups when your operating (not good) Now slide your cups into the holes you cut narrow end first with the sleeves facing out. Make sure the cup pokes through the plastic sheeting. Press the sheeting arround the cup on the inside and hot glue it to the box/sheeting. Make a decent seal with the glue, all the way arround the cups.
That is pretty much it. it may sound like a lot of work, but trust me this box works fantastic. It works ten million times better than my old glove boxes that I built when i first started. I had one with a dishcloth front and all kinds of nonsense lol.
Using Brick Top
Now the important part! Proper procedure when using the GB.
Rule #1 - DO NOT USE LYSOL OR ANY OTHER FLAMABLE CRAP TO SPRAY YOUR GB. Not only is this dangerous, but it can also cause mutation and/or kill your work. You dont need any of that trust me.
Rule # 2 - WORK VERY VERY SLOWLY! No sudden movements! He could bite you if he knows your scared!
Ok, so you wanna work sterile ehh. Lets do a pretend procedure here. You got 10 qt jars that are ready to be innoc'd with ohh hell lets say g2g.
first, spray the entire inside of the gb with 10% bleach.
Wipe it down.
Lay down few sheets of paper towles on one side of the gb (to small stuff on)
Alcohol wipe a spoon and butane lighter and put it on the paper towel inside
LOOSEN THE LIDS of 5 qt jars (do 5 at a time!)
Spray jars all over with the bleach water
Put jars inside against the back wall of gb
Spray our master jar with bleach water after loosening lid and put inside
Give a shot or two of bleach water inside the gb
Place plexiglass on
Put light on top and turn on
put brick on to get a good seal on the top with the weatherstripping
Wash your gloved hands with antibacterial soap
Spray your gloved hands with the bleach water real good
Spritz entire area arround gb with bleach water
insert hands through plastic sleeve arm holes
completely loosen all lids first so they will come of real easy when ready
Flame your spoon with the butane lighter real good
Open the master jar and CAREFULLY/SLOWLY use the spoon to break up the grains.
I break up enough for 2 jars at a time
CAREFULLY/SLOWLY remove the lid from 2 jars and spoon in about 3-4 spoonfulls
repeat untill all 5 jars are done
I loosely lay the lids on after spooning and tighten fully after all have been innoc'd
Make sure all lids are tight (especially master!) and remove bricks and light and take top off
take your jars out and shake em, put in incubation
repeat until you have G2g'd your heart out. A qt should do at least 10 jars.
The number one thing is DONT MOVE TOO FAST! You want the air in there to be as still as possible. Practice 5 times before you try and do something vital. Dont try and do too much at a time. any more than 7 or 8 jars inside the box at a time can really cramp it up in there and make it hard to work properly. It goes faster to do small batches and over and over than filling the box to capacity.
This box has done everything from pouring agar to isolating on agar to g2g. it works. If you work slowly and confidently with skill you will get 0 contams.
There is no need to wait 2 hours or whatever like you where using lysol. Spray with bleach, fill it up, seal it up, and work!
This is my first tek so if its hard to understand or you got some Q's just lay em on me i can take it!
Posted 30 April 2005 - 06:09 PM
Since it is impossible to take pictures with your hands in a gb, all you get is a pic of the box sprayed with bleach and a pic of the items prepped and ready to set lid on and work. All petris and loop and lighter were wiped down with alcohol before being placed in the box. You (your FOAF) too can do agar work with this simple and effective GB that you can make at home!! (insert background music here)
Also, if anyone does make the good decision to make a box like this, please post a pic of it here yo! You have no idea the accomplishment I will feel if someone uses this tek! It works fo shizzle.
Posted 30 April 2005 - 06:31 PM
Posted 30 April 2005 - 07:45 PM
seriously though, plastic tub might work fine but he didnt have one lying arround. Plus plexiglass is easier to see through than any plastic tub lid ive seen before. I supose you could just put the plexi on top of a plastic tub as well (with weather stripping) and get best of both worlds.
Posted 30 April 2005 - 08:20 PM
I noticed you said you had trouble lining your glovebox with plastic, there is a simple solution. A cardboard box is made out of one sheet of cardboard cut from a pattern and folded in a specific way. As a result, there is always a seam along one corner of the box where one edge of the pattern was glued to a folded tab sticking off the other edge. When I built my box, I used a utility blade (a sharp kitchen knife works well too) to separate the tab from the edge where it was glued. Simply find the seam, carefully insert the blade between the tab and the edge that is glued, and carefully work it down along the seam. When you get to the bottom you should have an intact edge and a tab running along the length of what was one edge of the box. Now you can unfold the box and lay it out flat. Get a can of high strength spray adhesive (I recommend 3M "Super 77" spray adhesive) and a big sheet of 4mil plastic. Both can usually be found at Home Depot or automotive parts/supply stores.
Make sure the side of the cardboard that will be the inside of the box when it is folded, is facing up when it is laid out on the ground in the work area. Now cut a piece of plastic sheeting that is just a little bit larger than your unfolded cardboard box, use some of the extra sheeting as a dropsheet behind the cardboard to catch the overspray. Roll up the sheet of plastic you cut down to be approximately the size of the box, and lay it along one edge of the box with the rolled part facing up, so you can unroll it as you work your way down the length of the cardboard with the spray adhesive. Then follow the instructions on the can of adhesive to attach the plastic to the cardboard permanently. Make sure you really coat the surfaces with adhesive, and press the plastic down into the ridges where the cardboard will fold. Also, don't just coat the whole thing with adhesive and try to lay the plastic on it. You should work at one end and move down the cardboard spraying/gluing inch by inch, pressing out any air bubbles that form. Once it is dry, fold the box up, and use epoxy or a similar strong adhesive to glue the tab to the same edge it was glued to before. You may want to rough up the plastic where the tab will meet the edge, so that it will hold better. Then just follow Sandmans tek.
As I said, I used a similar design for a while, except mine was postive pressure, there were thick rubber gloves mounted on the wall, the top was sealed with plastic wrap when I was working, and the bottom work surface was covered with tinfoil. It is a good, reliable design that takes up much less space than a tub style glovebox when it is folded down for storage. Hope this helped!