Lyven protocol
• For each erlen: following of starch hydrolyze
–
–
–
–
Removal of 0.5 ml of starch solution
Adding 2.5 ml iodine reagent Composition
Mixing by reversal
Read optical density at 630 nm
• At the beginning starch is blue dark. Then it
turns to brown when it is transformed in dextrin
with amylase activity. At the end of hydrolyze the
solution stay yellow
Starch
Dextrin
Time of hydrolyze with amylase
2,000
DO - 630 nm
1,500
1,000
0,500
0,000
5
15
25
35
Tim e
45
55
Iodine reagent
Return
• Iodine concentrated solution:
– 4.4 g of potassium iodure (KI)
– 2.2 g of iodine (I2)
– Dissolve successively in about 20 ml of distilled water, complete
to 100 ml
– Store this solution in dark glass maximum one month
• Iodine reagent:
– Dissolve 4g of potassium iodure in about 80 ml of distillated
water
– Add 0.4 ml of iodine concentrated solution
– Complete to 100 ml with distilled water
– Store maximum one day
• Individual protection equipment is recommended for
iodine handling