The Chromogranin A test kit is an enzyme-linked immunosorbent assay (ELISA) for detection and quantitation of chromogranin A in human plasma or serum. The results of the assay may be used as an aid in the diagnosis of chromogranin A secreting neuroendocrine tumours (NETs), such as phaeochromocytomas and carcinoids. The assay is intended for use in patients with signs and symptoms consistent for NETs. It is not intended for screening a healthy population.