The only test I have heard of is the The Sabin-Feldman dye test. It is a laboratory tests for the diagnosis of Toxoplasmosis.
A single-celled parasite called Toxoplasma gondii causes a disease known as toxoplasmosis.
Toxoplasma infection, however, should be considered in patients with Crohn's disease who are over 40 years old, and who present with nonspecific signs of intercurrent infection.
I am not sure if this is the dye test your referring to. Hopefully someone else has better info for you.
Hope you find your answer. Take care