Histology FAQ
Staining, Histochemistry and Histotechnology
(Frequently Asked Questions)
Dr. John A. Kiernan
Department of Anatomy
and Cell Biology
The University of Western Ontario
London, Canada
Diastase
(amylase) control for glycogen
Question.
Which is better as a control for glycogen staining: alpha-amylase or human saliva?
Answer.
The bought enzyme (10 mg/ml, in water) takes about 10 minutes to remove the stainable glycogen from a section of liver. The enzyme is not very expensive.
Saliva is free, and it takes about 30 minutes, but some people don't enjoy spitting, or even dribbling, onto their slides. A theoretical disadvantage of spit is that it contains plenty of digestive enzymes additional to amylase (= diastase), notably ribonuclease and various proteases. However, these are unlikely to remove substances with the same staining properties as glycogen.
John A. Kiernan
London, Canada
(kiernan[AT]uwo.ca)