Fluorokine human mmp multi analyte profiling base kit

Concentrations of MMP-1, MMP-3, MMP-13 and IL-6 were determined by immunoassays with commercial reagents according to the protocol provided by the manufacturer (human total MMP-1, human total MMP-3, human total MMP-13, mouse total MMP-3 and mouse IL-6 ELISA kits were from R&D Systems; human IL-6 ELISA kit was from Sanquin, Amsterdam, The Netherlands; MMP-1 in SF was determined by Multiplex bead array, Fluorokine® Human MMP Multi Analyte Profiling Base Kit, purchased from R&D systems). Nitrite, stable metabolite of nitric oxide (NO), was measured in the culture media by the Griess reaction [32 (link)]. The cartilage culture media samples were filtered through Amicon Ultra 10-K filters (from Millipore, Cork, Ireland) at 14,000 g prior to the Griess analysis in order to remove large proteins that might interfere with the Griess analysis.

Concentration of IL-6 in plasma, synovial fluid, and culture media was measured by enzyme-linked immunosorbent assay (ELISA) with commercial reagents from Sanquin (Amsterdam, The Netherlands). The detection limit for IL-6 was 0.3 pg/mL. MMP-1 concentrations in the synovial fluid were determined by Multiplex bead array (Fluorokine^® Human MMP Multi Analyte Profiling Base Kit, R&D Systems, Inc., Minneapolis, MN, USA) and MMP-3 concentrations were assessed by ELISA (R&D Systems, Inc.). Detection limits were 10.7 pg/mL for MMP-1 and 15.6 pg/mL for MMP-3.