Acetylcholine Receptor Binding Antibody

Acetylcholine Receptor (Muscle AChR) Binding Antibody, Muscle AChR, Myasthenia Gravis (MG)

Test Codes

EPIC: LAB1231920, Beaker: ACHR Bind, Quest: 206

Department

Send Outs

Specimen Collection Criteria

Collect (preferred specimen): One Gold-top SST tube.

Also acceptable: One plain Red-top tube. 

Physician Office/Draw Specimen Preparation

Let specimen clot 30-60 minutes then centrifuge to separate serum from cells. Transfer serum to a plastic transport tube and keep at room temperature (20-26°C or 68-78.8°F).

Preparation for Courier Transport

Transport: 1.0 mL serum, and keep at room temperature (20-26°C or 68-78.8°F). (Minimum: 0.5 mL)

Rejection Criteria

• Plasma
• Gross hemolysis
• Grossly lipemic
• Microbially contaminated
• Specimens not collected and processed as indicated.

In-Lab Processing

Let specimen clot 30-60 minutes then centrifuge to separate serum from cells. Transfer serum to a plastic transport tube and keep at room temperature (20-26°C or 68-78.8°F).

Transport: 1.0 mL serum, refrigerated (2-8°C or 36-46°F). (Minimum: 0.5 mL)

Storage

Specimen Stability for Testing:

Room Temperature (20-26°C or 68-78.8°F): 14 days
Refrigerated (2-8°C or 36-46°F): 14 days
Frozen (-20°C/-4°F or below): 30 days

Specimen Storage in Department Prior to Disposal:

Specimen retention time is determined by the policy of the reference laboratory. Contact the Send Outs Laboratory with any questions.

Laboratory

Sent to Quest Diagnostics, Wood Dale, IL.

Performed

Tuesday – Saturday.
Results available in 3-4 days.

Reference Range

Negative: ≤0.0 - 0.4 nmol/L.
Equivocal: 0.31-0.49 nmol/L.
Positive: ≥0.50 nmol/L or greater. 

Test Methodology

Radioimmunoassay (RIA).

Clinical Utility

Acetylcholine Receptor Binding Antibody – Myasthenia Gravis (MG) is an autoimmune neuromuscular disorder characterized by muscle weakness, most commonly due to autoantibody-mediated loss of functional acetylcholine receptors (AChR) in the neuromuscular junction. AChR binding autoantibodies are diagnostic of MG and are found in 85-90% of MG patients. This assay aids in the differential diagnosis of conditions with MG-like muscle weakness and in monitoring therapeutic response. If binding antibodies are negative, assays for modulating and blocking antibodies should be considered.

CPT Codes

86041

Contacts

Last Updated

11/19/2025