BÜHLMANN sCAL ELISA:
Hurnakova J et al.: Serum calprotectin (S100A8/9): an independent predictor of ultrasound synovitis in patients with rheumatoid arthritis. Arthritis Research and Therapy. 2015: 17:252. PMID: 26373925 doi: 10.1186/s13075-015-0764-5