Test Directory

Clear All
Test Code
MUSK
Test Name
Muscle-Specific Kinase (MuSK) Autoantibody
CPT Codes
86366
Expected Turnaround Time
4 - 8 days
Clinical Utility

Detection of antibodies to muscle-specific receptor tyrosine kinase (MuSK) (titer test). MuSK autoantibodies are detected using an RIA; a titer of 1:10 or greater is considered positive for antibody presence and provides a definitive diagnosis of MG.
Specimen and Container Info

Specimen Type: Serum

Preferred Collection Container: Red Top, Plain

Alternate Collection Container: Gold Top, Serum Separator

Desired Specimen Volume: 2 mL
Collection Instructions
  1. Collect a red top, plain tube via venipuncture.
Processing and Submission Instructions
  1. Separate serum from cells within 48 hours of collection.
  2. Transfer 2 mL of serum to a clear aliquot tube (screw cap).
Transport Instructions

Transport to the laboratory refrigerated. 
Stability Requirements

Room Temperature

72 hours

Refrigerated

42 days

Frozen

1 year
Causes for Rejection
  • Hemolysis
  • Lipemia
Methodology
Radioimmunoassay
Reference Intervals

See patient report.
Alternate Names
  • MuSK Antibody Test
  • muscle-specific receptor tyrosine kinase
Reference Lab
Quest Diagnostics Nichols Institute
Testing Schedule
Routine, 6 times per week
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.
© 2026 HNL Lab Medicine. All rights reserved.