Synovial fluid derived from post mortem horses colelcted at an abattoir. Synovial fluid was from the metacarophalangeal joint.  At collection synovial fluid was immediately placed on ice and then centrifuged for 10 min at 3000 g 4oC. The supernatant removed and stored at -80oC. Synovial fluid was treated to reduce viscosity with 1µg/ml of hyaluronidase at 37˚C for 1 hr, centrifuged at 1,000g for 5 min, and supernatant used for total RNA extraction using miRNEasy serum kits (Qiagen, Crawley, UK).   Trizol followed by miRNAEasy Serum kit (Qiagen) Small RNA Library Prep Set for Illumina (New England Biosciences (NEB), Ipswich, USA) but with the addition of a Cap-Clip™ Acid Pyrophosphatase (Cell script, Madison, USA) step to remove any 5' cap structures  and size selected using a range 120-300bp
Experimental Factor: disease staging
severe