Question

how will you test the presence of protein

Answer 1

Protein - Biuret solution. Biuret solution is used to identify the presence of protein. Biuret reagent is a blue solution that, when it reacts with protein, will change color to pink-purple.

Answer 2

Buiret solution is a blue liquid that changes to purple when proteins are present and to pink in the presence of short chains of polypeptides. 
hope it help you.