High Quality Content by WIKIPEDIA articles! A MELISA (Memory Lymphocyte Immunostimulation Assay) test is a blood test that detects Type-IV allergy to metals, chemicals, environmental toxins and molds from one single blood sample. It can also identify active Lyme disease (Lyme Borreliosis). The test does not measure toxicity-that is to say, it will not measure the amounts of a harmful substance in the patient`s blood. It measures if the patient is allergic to it.