Table 2.

Summary of recommendations for preanalytical aspects of AD biomarker testing in CSF.

Possible variability factor	Recommendation
CSF gradient	No gradient observed
Lumbar puncture	L3–L4 or L4–L5
	22G atraumatic needle to reduce the risk of blood contamination
Fasting	Not required
Tubes	PP (polypropylene)
Aliquotation	Aliquot the samples in small volumes (0.25 or 0.5 ml tube)
	Fill the tube up to 75%
Centrifugation	2000 × g for 10 min at room temperature
Time before storage	Up to 5 days
Temperature before storage	4°C
Freezing	–80°C
	–20°C for no longer than 2 months
Freeze/thaw cycles	No more than 1–2