This test assists in the diagnosis of autoimmune myasthenia gravis (MG) with acetylcholine receptor (AChR) antibodies.

It provides a more sensitive test for AChR antibodies that may be present in double-seronegative samples, but undetectable by standard detection methods such as radioimmunoprecipitation assay (RIPA) or enzyme-linked immunosorbent assay (ELISA).

Test code:


Abbreviations, alternate names::

Clustered AchR Ab, AchR Ab


In-house live cell-based assay (CBA)


Specimen type:


Minimum volume:

0.5 mL

Preferred volume:

3 mL

Rejection criteria

Grossly hemolytic, lipemic, or icteric. If the sample arrives at room temperature.

Our offices are only able to receive samples Mon-Fri, so samples must be shipped Mon-Thur. Samples arriving over the weekend may need to be re-drawn.


Specimen collection:

No patient preparation is required for sample collection.
Draw blood in tube(s) with SST activator (5mL gold top or 8.5mL tiger top).
Invert tubes 8 times to ensure complete mixing.

Specimen handling:

Centrifuge SST tubes at 1800 - 2200 x g for 10-15 minutes
Draw off serum (top layer) into Aliquot tubes with pipette, ensuring not to take gel or RBC (middle/bottom layers)
Store Aliquot tubes in refrigerator (2°C - 8°C) until shipping.

Specimen stability:

Serum samples may be stored:
Up to 24 hrs at room temp (15 - 25°C)
Up to 7 days refrigerated (2 - 8°C)
Up to 2 freeze / thaw


Testing frequency:

Once a week

Turnaround time:

2-7 days

Reference Range:


Additional Information

  • This test was developed and its performance determined by Neurocode USA Inc. It has not been cleared or approved by the Food and Drug Administration.
  • Please indicate if patients are on immunomodulating treatments as these may interfere with testing.
  • Causal antibodies cannot be identified in about 10% of MG cases. Therefore, a positive result is specific for the diagnosis of AChR ab myasthenia gravis (MG), but a negative result does not rule out an MG diagnosis.