THIS IS A QUALITATIVE TEST FOR HETEROPHILE ANTIBODIES TO INFECTIOUS MONONUCLEOSIS. HETEROPHILIC ANTIBODIES ARE ASSOCIATED ALMOST EXCLUSIVELY WITH INFECTIOUS MONONUCLEOSIS AND EB VIRUS ASSOCIATED NEOPLASMS. USUALLY THESE ANTIBODIES DEVELOP 3 WEEKS AFTER INFECTION, BUT SOME PATIENTS MAY TAKE AS LONG AS 3 MONTHS TO DEVELOP THE ANTIBODIES.