Re: What is a DNS reagent?

The reagent 3,5-dinitrosalicylic acid is commonly used for the assay of the 
enzyme amylase. The enzyme company Worthington Biochemicals publishes a 
book called the Worthington Manual which has detailed protocols on assaying 
a variety of common enzymes. You can read a copy of this on the internet. 
The URL for the manual on line is


http://www.worthington-biochem.com/manual/manIndex.html

and you should look up the references for amylase.

Good luck with your experiments.