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Beta Amyloid 42/40 Ratio, CSF

CPT: To be determined. Updates will be made when available.

Special Instructions

This test is not approved for NY state clients.

Related Documents

Specimen Requirements


Cerebrospinal fluid (CSF)


8 mL

Minimum Volume

5 mL


Sarstedt CSF Tube 62.610.018. Tube provided by Labcorp by request.


Collect cerebral spinal fluid (CSF) in Sarstedt CSF Tube 62.610.018. Tube must be filled 50% to 80% minimum.

Storage Instructions

Refrigerate immediately (preferred), within 8 hours.

Stability Requirements



Room temperature

8 hours


8 days


30 days

Freeze/thaw cycles

Stable x1

Causes for Rejection

Wrong tube type; not stored at proper temperature; quantity not sufficient

Test Details


To indicate the ratio of beta-amyloid 42 proteins to beta-amyloid 40 proteins measured in the CSF to aid in the assessment of disease progression in patients with suspected or probable Alzheimer's disease.


Chemiluminescent enzyme immunoassay (CLEIA)

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