We apply fluorescence correlation spectroscopy (FCS) and dynamic light scattering (DLS) to measure both the translational diffusion coefficient, D, of different fluorescent probes embedded in Ficoll solutions and the density fluctuations of the Ficoll solutions. Ficoll (MW=70 kDa) is a water-soluble, branched polysaccharide usually considered to be a spherical nanoparticle. The probes (R6G, dextran10, R-Erythrin proteins, clathrin, polystyrene beads,..) vary not only in size (1.8 nm to 34 nm) but also in shape (globular, branched polymers, triskelia). We find, using FCS, that the decrease of D as a function of Ficoll concentration (up to 500 mg/ml) can be described by an exponential, exp(-αc), with α being dependent on the probe size. This can interpreted within a model proposed by DeGennes and co-workers, which predicts a stretched exponential, D ∼exp(-αc-ν), with ν being related to the solvent quality and α proportional to the probe size. Thus, ν≈1, indicating a θsolvent like quality for the water-Ficoll system. The DLS measurements were performed as a function of the scattering angle and Ficoll concentration. At low concentrations (< 1mg/ml), we determined the hydrodynamic diameter of the Ficoll to be about 11 nm. As the Ficoll concentration is increased, a second mode appears in the correlation function, indicating possible interactions between the Ficoll polymers. We fitted the correlations with double stretched exponentials and determined the relaxation times of both modes as a function of the concentration. While one mode increases by several orders of magnitude, the other decreases weakly and exponentially, whose prefactor depends on the scattering angle. Estimates based on packing criteria of spherical beads show that the Ficoll polymers must intertwine in order to fit the volumetric space, indicating that Ficoll polymers are not compact nanoparticles and confirming the observations from DLS.