Serum in plain tube (red top) or SST tube (yellow top) or in a separation vial. Centrifuge tubes within 1 hour. Separate centrifuged serum in plain tubes within 1 hour.
Clinical Utility
Evaluate rheumatoid arthritis (RA) as one component of a multi-criteria diagnostic process that co-opts clinical & other lab criteria (refer to current ACR/ EULAR criteria for diagnosis of rheumatoid arthritis). It is more specific for RA than rheumatoid factor.