SRP (Signal Recognition Particle)

Category: Rheumatology
Test Code: 053
Disease: Dermato/Polymyositis
Methodology: Line Immunoassay
Reference Range: Qualitative
CPT Code: 84182
Schedule / Turnaround Time: Assay performed once every two weeks. Report availability is two weeks from the time of specimen receipt.
Specimen Requirements:

Specimen need not be refrigerated or frozen. Collect 2-3 ml of blood in a red top or serum separator tube. If possible, separate serum from clot and place into white tube provided with Immco Diagnostics’ collection kits. If separation facilities are not available, the blood can be sent in the tube used for collection.

Sample Stability:

Sample is stable at ambient temperature during shipment. If sample is stored prior to shipment, it is stable refrigerated (2-8˚C) up to five days and frozen (-20˚C or lower) up to one year.


The presence of SRP antibodies is predominantly associated with polymyositis. The prevalence of SRP antibodies in idiopathic inflammatory myopathy is 4-5%.