Ordering Recommendation

Recommended for differential evaluation of neuromuscular junction diseases including myasthenia gravis (MG).

New York DOH Approval Status

This test is New York state approved.

Specimen Required

Patient Preparation

Serum separator tube.

Specimen Preparation

Separate serum from cells ASAP or within 2 hours of collection. Transfer 1 mL serum to an ARUP Standard Transport Tube. (Min: 0.15 mL)

Storage/Transport Temperature


Unacceptable Conditions

Plasma. Contaminated, hemolyzed, or severely lipemic specimens.


After separation from cells: Ambient: 48 hours; Refrigerated: 2 weeks; Frozen: 1 year (avoid repeated freeze/thaw cycles)


Semi-Quantitative Indirect Fluorescent Antibody




1-4 days

Reference Interval

Less than 1:40

Interpretive Data

When detected in the presence of acetylcholine receptor (AChR) antibody, striated muscle antibodies, which bind in a cross-striational pattern to skeletal and heart muscle tissue sections, are associated with late-onset myasthenia gravis (MG). Striated muscle antibodies recognize epitopes on three major muscle proteins, including: titin, ryanodine receptor (RyR) and Kv1.4 (an alpha subunit of voltage-gated potassium channel [VGKC]). Isolated cases of striated muscle antibodies may be seen in patients with certain autoimmune diseases, rheumatic fever, myocardial infarction, and following some cardiotomy procedures.

This test was developed and its performance characteristics determined by ARUP Laboratories. It has not been cleared or approved by the US Food and Drug Administration. This test was performed in a CLIA certified laboratory and is intended for clinical purposes.

Compliance Category

Analyte Specific Reagent (ASR)


If Striated Muscle Abs detected, a titer will be added. Additional charges apply.

Hotline History


CPT Codes

86255; if reflexed, add 86256


Component Test Code* Component Chart Name LOINC
0050747 Striated Muscle Antibodies, IgG Screen 49692-7
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.


  • Anti-Skeletal Muscle IgG Antibodies
  • Anti-Striated Antibody
  • Anti-Striated Muscle Antibody
  • Muscle (Skeletal) Antibodies
  • Myoid Antibody
  • Skeletal Muscle Antibodies
  • Striational Antibodies
Striated Muscle Antibodies, IgG with Reflex to Titer