A simple, fast, reliable, and specific immunoassay has been developed to detect and measure AD7C-NTP, a biochemical marker for Alzheimer's disease, in cerebrospinal fluid (CSF). This assay, called the AD7C Test, is an enzyme-linked sandwich immunoassay (ELSIA) using 96 well microtiter plates. The plate surface is coated with a monoclonal antibody (N3I4) which has a high affinity and specificity for AD7C-NTP, capturing it effectively from CSF samples. The detection was achieved using a polyclonal antibody (ADRI). Both N3I4 and ADRI were generated using recombinantly produced AD7C-NTP. The assay is highly sensitive (30-50 pg), linear to 2.0 ng (r2 > 0.99), and reproducible (C.V. < 10%). The utility of the assay has been demonstrated using CSF specimens from early Alzheimer's disease patients and age matched controls (sensitivity of 89% and specificity of 89%).