Australia's Science Forum

Hi
One of my teachers always has trouble getting the amylase to work. We get it from Southern Biological. Does anyone else encounter this problem.
Krysia

We get ours also from S.B.
Just finish doing an experiment and worked well. We use 0.1% amylase and 1.5% starch. We use equal amounts of starch and amylase.
Glucose is detected by Benedicts test.

Lada

I think there are 2 different types of Amylase - diastase and catalase. It is the diastase that you need to use. Just check you have the right one. Do a seach here for amylase and you'll probably find some previous discussions on this. Good luck!

I did not know that, but we do have diastase.
Thanks for the tip.
Lada

Also the diastase powder should be stored in the fridge. As it's an enzyme I make up the solution fresh (the day before), store it in the fridge overnight and aliquot it just before the prac. We use 5 ml of 0.5% diastase solution with 10 ml of 0.5% starch, and it works really well. Also make sure your iodine gives a good strong reaction with the starch, as it does go off.

good luck

As Kate pointed out, make up the solution of amylase as fresh as possible. On the day of use, if you can.
And always store the powder in fridge.
Lada

Yes, we had some problems too, but that was more because the prac was very vague with no concentrations mentioned. Once I sorted that out, it seemd to work okay, although we used a bread and water solution rather than a known concentration for a starch solution. I think next year we will have to look at changing the method a bit!

I have the amylase Clarase, perhaps thats my problem. Thanks for all the replies.
Krysia

According to SB, clarase is ok as long as you are only testing for the breakdown of starch as clarase has some reducing sugars in it. If you are also doing the benedicts solution test for sugar production in the breakdown then you need diastase which doesn't have the reducing sugars added as otherwise they would interfere with the results.

Clarase!!! Yes, that's the other one. I knew catalase was wrong... but I couldn't think of what it was!

Hi helpful chemtalkers!
I have been asked for amylase solution - also asked for starch solution and iodine.

How do i make amylase soluntion - and i see that i should make it fresh just before I need it - so tomorrow morning it is!

THANKS!

I usually make a 1% amylase solution 1g in 100ml water.

thanks - thats what i was after <3