The hopkins-cole test is used to determine the presence of the amino acid tryptophan.
Tryptophan has an indole nucleus which is responsible for the violet ring found at the junction between the two layers.
Produces a Purple ring at the point of contact of the two liquids. :)
a purple /violet ring is formed at the junction .. that's what i get in our experiment.. and its correct..:)
pink to violet interface
fuchsia fuchsia
gdg