Evaluating cellular uptake of IDR-1002. Human fibroblast-like synoviocytes (FLS) were stained fluorescently to demonstrate the uptake of IDR-1002. The cells were stimulated with 100 μg/ml biotinylated IDR-1002 (IDR-1002B). Cells were either (a), not treated with peptide, or stimulated with IDR-1002B for (b), 0 minutes, (c), 15 minutes, or (d), 30 minutes. Cells were washed, fixed, and stained for actin by using Alexa Fluor 546 phalloidin (red) and stained with Streptavidin Alexa Fluor 488 conjugate to detect IDR-1002B (green). Hoescht 33258 was used to counterstain the nucleus (blue). The scale bar in (d) represents a length of 50 μm. IDR, innate defence regulator.