Ordering Guidance

This test is intended for use in adult patients aged 55 years and older. If evaluating an individual 54 years or younger, order ADEVL / Alzheimer Disease Evaluation, Spinal Fluid.

This test only measures the beta-amyloid ratio (1-42/1-40) in cerebrospinal spinal fluid. Individual beta-amyloid 1-42 and 1-40 concentrations are not reported. If measurement of additional neurodegeneration markers such as total Tau, phosphorylated Tau (p-Tau181), beta-amyloid (1-42), and the p-Tau/beta-amyloid 42 ratio are desired, order ADEVL / Alzheimer Disease Evaluation, Spinal Fluid.

Specimen Required

Container/Tube:

Preferred: Sarstedt 1.5 mL tube (Ref. 72.703.600), Collect at least 750 mcL of cerebrospinal spinal fluid (CSF) or (≥50% full).

Acceptable: Sarstedt CSF False Bottom Tube 63.614.625 (2.5 mL), Sarstedt 72.694.600 (2 mL) or Sarstedt 10 mL tube Ref. 62.610.018 (Collect at least 5 mL of CSF [≥50% full]).

All tubes should be filled to between 50% to 100% of the total empty container volume. Specimens received with less than the required fill volume may be rejected.

Specimen Volume: 0.75 to1.5 mL or at least 50% container volume

Collection Instructions:

1. This test is intended for use in adult patients, aged 55 years and older. Do not collect CSF for this test if the patient is younger than 55 years of age.

2. Perform lumbar puncture and discard the first 1 to 2 mL of CSF. Note: CSF collection should be performed by the gravity drip method.

3. Discard any visibly blood contaminated CSF.

4. Collect CSF directly into one of the listed collection tubes until the tube is at least 50% full.

5. If transporting frozen, freeze sample upright prior to placing in transport container.

6. If transporting refrigerate, tubes should be transported upright.

Note: Polystyrene collection tubes are not acceptable. Exposure of CSF to polystyrene tubes may result in falsely low beta-amyloid concentrations. For more information see Cautions.

7. Collection instructions can also be found on Spinal Fluid Specimen Collection Instructions for B-Amyloid (1-42/1-40) (T979).