ABeta 40; ABeta 42; ABeta 42/40 Ratio
This LC-MS/MS assay measures beta-amyloid 40 (AB40) as well as AB42 in plasma, rather than AB42 alone. This permits the normalization of beta amyloid levels circulating in plasma in different patients. Using the ratio of beta-amyloid 42/beta-amyloid 40, improves sensitivity and specificity for detecting Alzheimer's disease.
Quest Diagnostics does not perform this test for individuals under the age of 18.
Pre-test and post-test counseling is strongly recommended.
* This volume does not allow for repeat testing
Collect blood into a K2 EDTA plasma tube and mix by inversion 10 times.
Centrifuge to separate plasma from cells within 1 hour of collection.
Carefully transfer plasma into a polypropylene tube or one of the Quest issued polypropylene pour-off/transfer tubes. Do not transfer to conical tube.
Moderate or gross hemolysis
Specimen collected in a glass tube
Specimen collected in a polystyrene tube
Specimen collected in a polycarbonate tube
Transport
Store
Store
| ABeta 42 | Not established | pg/mL |
| ABeta 40 | Not established | pg/mL |
| ABeta 42/40 Ratio | ≥0.170 |
This LC-MS/MS assay measures beta-amyloid 40 (AB40) as well as AB42 in plasma, rather than AB42 alone. This permits the normalization of beta amyloid levels circulating in plasma in different patients. Using the ratio of beta-amyloid 42/beta-amyloid 40, improves sensitivity and specificity for detecting Alzheimer's disease.
This test was developed and its analytical performance characteristics have been determined by Quest Diagnostics. It has not been cleared or approved by FDA. This assay has been validated pursuant to the CLIA regulations and is used for clinical purposes.
4 to 6 days
00913333
82233, 82234