Beta Amyloid 42/40 ratio, plasma

Alphabetical Test listing

Beta Amyloid 42/40 ratio, plasma-994

Test name:

Test number:

994

Excellian order number:

LAB994

Abbreviation:

MSO

Alternate names:

AD-Detect
42/40 ratio
Alzheimer's lab test
B-Amyloid

Useful for:

The plasma A42/40 ratio is intended for use as an adjunct to diagnostic evaluations of Alzheimer's disease, including neurological and cognitive performance examinations and PET neuroimaging.

Specimen type:

EDTA plasma

Collection container:

Lavender (EDTA), 4mL

Volume:

2 mL

Minimum volume:

1 mL

Collection instructions:

Immediatley following collection, mix sample thoroughly by gently inverting 8 - 10, times to prevent clotting

Processing instructions:

Spin within 40 minutes of sample collection
Transfer plasma to a Screw-cap polypropylene frozen transport vial/tube - 4mL (LabCorp), labelled as EDTA plasma

Transport container:

Screw-cap polypropylene frozen transport vial/tube - 4mL (LabCorp)

Transport and stability:

Frozen (preferred) - 100 days (-70°C)

Frozen - 24 hours (-10°C)

Refrigerated - 10 hours

Ambient - 4 hours

Reason for rejection:

Hemolyzed or lipemic specimens
Heat-treated specimens
Gross bacterial contamination

Performing lab:

LabCorp (505725); R-NX

TAT:

5 - 6 days

Method:

Sysmex chemiluminescence enzyme immunoassay (CLEIA)

Reference ranges:

See report

CPT codes:

82233
82234

Date created:

01/24/2024

Revised date:

07/28/2026

Review date:

07/27/2026