Australia's Science Forum

Please help! This is my first day on the job by myself!
I can not remember how Okker told me to seperate the dialysis tubing.

use 10 cm dialysis tubing that has been soaking in water. Twist one end of the tubing and fold it over, then tie off that end with string to form a bag. To open the other end of the bag, rub the end between your thumb and forefinger until the sides separate

I wet it, tie a knot in the bottom (really really tightly tied) and then separate it at the the top.

THEN i blow into it, to make it look like a little sausage, and stand it upside down over the pegs on a test tube rack and let it dry. Then what you have is dry, slightly crackly open tubes that the kids can pour liquid into with wa-a-a-ay less fuss and mess!

Hi,

If you want to seperate the tubing in it's dry form, get a couple of pieces of sticky tape, place on each side of the tubing and pull open. You can then blow into it to open up the rest of the tubing.

Brilliant. I leave a paddle pop stick inside and wiggle it down as I take a length off.

Hi everyone! So I was just getting the dialysis tubings ready based on what I've learned here for a prac scheduled tomorrow afternoon, and as I was doing so, the teacher saw me & told me not to do that as it will turn dry & yucky by tomorrow & they won't be able to use it. Is that true?

& here I was, so pleased with myself for putting into practice something I've read here, & she comes in & burst my bubble

Do they mean because it was wet and will dry out? Otherwise if you just opened it dry I can't see the problem? (We just cut to length and get the students to do the rest)

Her exact words were they will turn dry & yucky (not very scientific, I know). I've left out a couple of tubings that I've already tied, soaked & opened, & now letting them dry on a rack as described by @smiley. Will test them tomorrow & try to prove/disprove what she said.

Yup, I can actually just cut them to length & let the students do the rest. Gives me more time for other pracs that way.

Yes just cut them to size and the students do the rest, hopefully with proper guidance from the teacher. It is just useful to know how to set up the dialysis tubing in case you see a student struggling to get it done. I was originally shown by another lab tech to wet the tube under running water while rolling the end of the tubing between my fingers to loosen it up. Once the end is loose you continue to roll the rest of the tubing between your fingers under running water until it is nice and pliable and slippery. Then tie a knot in the loose end and you are ready to do the prac.
There is probably no reason why your prepared tubes can't be rewet and used, except for the students not having the experience in learning how to prepare their own tubing and do their own knots. Just make sure that you have given them an adequate length of tubing for tying knots in both ends and leaving enough room for the liquid that goes in between the knots.

Lyn wrote:Yes just cut them to size and the students do the rest, hopefully with proper guidance from the teacher. It is just useful to know how to set up the dialysis tubing in case you see a student struggling to get it done. I was originally shown by another lab tech to wet the tube under running water while rolling the end of the tubing between my fingers to loosen it up. Once the end is loose you continue to roll the rest of the tubing between your fingers under running water until it is nice and pliable and slippery. Then tie a knot in the loose end and you are ready to do the prac.
There is probably no reason why your prepared tubes can't be rewet and used, except for the students not having the experience in learning how to prepare their own tubing and do their own knots. Just make sure that you have given them an adequate length of tubing for tying knots in both ends and leaving enough room for the liquid that goes in between the knots.

Noted. Thank you so much!

For a cheaper way, little plastic bags from Liverstone, sorry to put the company name up, but over the years, it is the only one that does these bags. They work so very well, on the Iodine & Starch experiment.

I give the senior students cut lengths of dialysis tubing
The junior students get small freezer bags from Woolworths as they do the job just as well for junior students at a fraction of the cost.
We do have 7 or 8 junior classes in each year group so dialysis tubing can get rather expensive for them

fibreweb wrote:I give the senior students cut lengths of dialysis tubing
The junior students get small freezer bags from Woolworths as they do the job just as well for junior students at a fraction of the cost.
We do have 7 or 8 junior classes in each year group so dialysis tubing can get rather expensive for them

That's interesting, fibreweb! Any way we can cut cost is always welcome around here as budget is really tight. I will definitely mention that to my HOD. Thanks!