The established Innogenetics ELISA procedures have been well optimized to measure patient samples in the normal and pathological range. Compared to the MSD they were superior in the limit of detection for total as well as p-tau. The obtained reference values for our normal controls were in the upper third of the published studies. Innogenetics tau, Innogenetics p-tau181 and MSD t-tau differentiated the Alzheimer鈥檚 (n = 44) and minimal impairment group (MCI, n = 39) from normal controls (n = 37), but the MCI group was not statistically different from the normal controls. The MSD multiplex assay measured t-tau adequately but p-tau231 could not differentiate normal from pathological results in CSF due to the high limit of detection. Both procedures however, have to be further standardized and complemented by adequate internal and external quality control schemes to qualify for routine analysis in a medical laboratory.