Beta Amyloid 42/40 Ratio, CSF
Use
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.
Special Instructions
This test requires a dedicated Sarstedt CSF liquor low protein binding tube sent directly to the testing facility. Specimen must be collected directly in the Sarstedt tube.
Limitations
This test was developed and performance characteristics were determined by Labcorp. It has not been cleared or approved by the Food and Drug Administration. Ratios less than 0.058 indicate a higher likelihood of Alzheimer's, whereas values equal to or greater indicate a lower likelihood of Alzheimer's diagnosis. The assay should be used as an adjunct to neurological evaluation, including diagnostic imaging.
Methodology
Immunoassay (CLEIA)
Biomarkers
LOINC Codes
- 98584-6
- 33203-1
- 70072-4
- 98485-6
- 50398-7
- 75608-0
Result Turnaround Time
5-8 days
Related Documents
For more information, please review the documents below
Specimen
Cerebrospinal Fluid
Volume
8 mL
Minimum Volume
5 mL
Container
Sarstedt CSF Tube 62.610.018
Collection Instructions
Collect cerebral spinal fluid (CSF) in Sarstedt CSF Tube 62.610.018. Tube must be filled 50% to 80% minimum. Specimen must be collected in Sarstedt tube directly and cannot be transferred from a regular collection tube. If first 1 mL is hemolyzed, discard and continue to draw sample.
Storage Instructions
Refrigerate immediately (preferred), within 8 hours. Freeze on arrival (at Labcorp).
Causes for Rejection
Wrong tube type; not stored at proper temperature; quantity not sufficient; sample transferred from another tube; gross hemolysis
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 8 hours |
| Refrigerated | 8 days |
| Frozen | 30 days |