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After reading the thread on this, just want to confirm that diastase is either an amylase or another name for amylase and will break down starch. It's the "movement across the small intestine" prac. Thanks

I am very interested in that too. We bought a new batch and it was labelled diastase. I was told it is amylase. One class just finished the enzyme practical but techer was not impressed. He said it did not work. But I am not sure if it is the reagent or the kids.
Lada

Just looked up Biology Dictionary(how old school!!) says Diastase: amylase.

Amylase and diastase are the same thing. Be careful though as some of them are almost all filler. The Chemsupply one that we have says it contains extender but we found out it was actually 95% potassium sulphate. Some people had said that they weren't getting very good results with it. So when we were doing our enzyme EEI this year we decided to buy the expensive liquid stuff from Southern Biological. It is about $50 for 10ml and we have got through so much of it. The students keep changing their method and increasing the % they are using. So next year we are going back to the powder. If they are going to end up using 5% solution then it will probably work anyway and I can make loads of solution from one bottle of powder.
Anyway the answer is probably to just increase the % you are using to compensate for the potassium sulphate.

Thanks Nicky.
I will do that for tomorrow and see, if teachers notice any difference.
Laboratory manual recommends only 0.1% amylase, so I will make 1% to see the difference.
Lada

From what I remember it also works best at body temperature 37 odd degrees.

Wendy

Just remember that compared to good old fashioned spit, you have to use a very dilute starch solution to get good results. Also, in "The Laboratory" it says to make it up with a buffer solution of 0.9% NaCl, 0.01 CaCl at 0.1g amylase/100mL buffer.

Finally success!!
I used 1% amylase in 1% salt solution and 1.5% starch and it worked. I used to use 0.1% amylase in buffer but the new batch was not as pure and needed 10x the strength.
Thanks, guys

OK so the Yr 8 prac with 10% starch (I changed it from 20% which was solid) sounds like a fail! The prac is 3x dialysis tubes- one with 10%glucose, one with the starch soln and one with the starch and 2%amylase soln. Used more diastase in this one prac than in years and years of senior biol where I've always used 0.1% diastase. I really do not like some of the junior pracs and given it required "candles" instead of bunsens my radar should have gone off.

Need some help. Enzyme practical coming up. We use amylase and I make up 0.1% solution. It has always worked but last year we bought new bottle and we did not get good results . I think someone mentioned that the new batch needs to be stronger. Am I correct?
Lada

Unfortunately enzymes with the same name are not the same such as Amylase/Diastase. What to look for when purchasing or making up a solution is the number of units per gram that the powder has. A unit will be written like - "one unit will liberate 1.0mg of maltose from starch in 3 min at pH6.9 at 20 deg". Where the enzyme comes from makes a large difference in how many units per gram... but also has a large difference in cost. We used to purchase amylase that a 0.01% solution would work great but it costs in excess of $200 per gram. We use diastase now but it has a lot less units per gram so we have to adjust the concetration accordingly - we use 1 to 2% solutions.

Thanks, Ross
That explains a lot. Must make up stronger solution.Lada

Anybody knows the difference between amylase (clarase) and diastase?
I need to order some and suer which one would be better?
Lada

GEEEEEEEEEEEEZ I must have a Deficiency in both amylase/diastase