Elecsys® pTau‑181, Plasma
Use
The Elecsys® pTau‑181 plasma assay is intended to be used as an aid in the initial assessment for Alzheimer’s disease and other causes of cognitive decline in adult patients ages 55 years and older presenting with signs, symptoms or complaints of cognitive decline. A negative test result is consistent with a negative amyloid PET scan result and reduced likelihood that a patient’s cognitive impairment is due to amyloid pathology. A positive test result may not be consistent with a positive amyloid PET scan result and requires further investigation to determine whether amyloid pathology may be contributing to cognitive impairment.
Special Instructions
Not provided.
Limitations
Not provided.
Methodology
Immunoassay (ECLIA)
Biomarkers
pTau‑181
Protein
Result Turnaround Time
2-5 days
Related Documents
For more information, please review the documents below
Specimen
Plasma
Volume
1 mL
Minimum Volume
0.7 mL
Container
Lavender-top (EDTA) tube
Collection Instructions
Draw blood in lavender‑top (EDTA) tube. Invert to mix with preservatives. Centrifuge and transfer plasma to a labeled plastic transport tube.
Storage Instructions
Room temperature
Causes for Rejection
Serum specimen; improper labeling
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 2 days |
| Refrigerated | 7 days |
| Frozen | 3 months |
Other tests from different labs that may be relevant