Posted Date
Effective Date
Update Type Reference range changed
Order Code ADEVL



Alzheimer Disease Evaluation, Spinal Fluid

Order Code:                  ADEVL

Reference Laboratory:   Mayo ADEVL


Specimen requirements and reference range for Mayo Clinic Laboratories Alzheimer Disease Evaluation, Spinal Fluid, will be updated as follows effective May 31, 2023.  The Sarstedt CSF False Bottom Tube 63.614.625 (2.5 mL) will replace the CSF AD Biomarker Tube (2.5 mL) as the preferred specimen container. 


Collection Instructions: 1) Perform lumbar puncture and discard the first 1 to 2 mL of cerebrospinal fluid (CSF). 2) Collect CSF directly into one of the listed collection tubes until the tube is at least 50% full. 3) Send 1.5 to 2.5 mL CSF specimen in original collection tube. Do not aliquot. Store and transport refrigerated. The Alzheimer's Association consensus protocol for handling of CSF for clinical measurements of Abeta42 and tau recommends using the drip method for CSF collection and directly collecting into a low bind polypropylene tube. Although some clinicians prefer the syringe pull method due to speed of collection, the drip method reduces the risk of Abeta42 binding to the plastic of any syringe used.


Reference Range: Beta-amyloid (1-42) (Abeta42): >834 pg/mL; Total-Tau: < or =238 pg/mL; Phosphorylated-Tau 181: < or =21.6 pg/mL; p-Tau/Abeta42: < or =0.028.