[kindpriya]

I have a solution of chitosan of 1% concentration and I have glutaraldehye which is 25% concentrated. what should be the final volume of 1% and .1% glutaraldehye is added to solution. I am confused how much Glutaraldehye I have to add.

[Arkcon]

You need to add very small amount of your glutaraldehye stock solution to your chitosan solution, can you see how to get from 25 % to 0.1 %?  At any rate, you will slightly dilute your 1% stock in the process, but that might not be a significant for your application, I'm just being absolutely correct. 

P.S. never forget to include the placeholder zero when you write a concentration,  especially when you write it on the bottle by hand, a decimal by itself might not be noticed.  It happened to me, and it was all my fault when they made the mistake on my day off, and assumed I meant 1 M, instead 0.1M.