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Test Code
ADABR
Test Name
Quest AD Detect(R) Beta Amyloid 42/40 Ratio, P
CPT Codes
82233, 82234
Included Tests
  • ABeta 42
  • ABeta 40
  • ABeta 42/40 Ratio
Expected Turnaround Time
4-6 days
Clinical Utility

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.
Specimen and Container Info

Specimen Type: Plasma

Collection Container: Lavender Top (EDTA)

Desired Specimen Volume: 1.2 mL
Collection Instructions
  1. Collect a lavender top (EDTA) tube via venipuncture.
Processing and Submission Instructions
  1. Mix by inversion 10 times.
  2. Separate plasma from cells within 1 hour of collection.
  3. Transfer 1.2 mL of plasma to a clear aliquot tube (screw cap) and freeze immediately.
  4. If unable to centrifuge within 1 hour of collection, store tube on ice.
Transport Instructions

Transport to the laboratory frozen.

Stability Requirements

Refrigerated

72 hours

Frozen

-20° C: 32 days

-70° C: 77 days
Causes for Rejection
  • Moderate or gross hemolysis
  • Specimen collected in a glass, polystyrene, or polycarbonate tube
Methodology
Liquid Chromatography - Tandem Mass Spectrometry (LC-MS/MS)
Reference Intervals

See patient report.
Limitations

Quest Diagnostics does not perform this test for individuals under the age of 18. Pre-test and post-test counseling is strongly recommended.
Alternate Names
  • Quest AD-Detect® Beta-Amyloid 42/40 Ratio, Plasma
  • AB42/40
Reference Lab
Quest Diagnostics Nichols Institute
Testing Schedule
Routine, Monday - Saturday
The American Medical Association (AMA) Current Procedural Terminology (CPT) codes published by HNL Lab Medicine are guidelines and are intended for informational purposes only. CPT coding is the exclusive responsibility of the billing entity. View the Terms.
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