Particle exclusion assays are used to visualize pericellular envelopes with a high content of hyaluronan. Pericellular hyaluronan is basally abundant in certain cell types while in others it is deposited in a highly dynamic manner in response to specific conditions and its presence may indicate cellular status. This assay, described here, is a quick semiquantitative approach to detecting pericellular hyaluronan using the hyaluronan-binding proteoglycan, aggrecan, to stabilize and amplify the surface matrix. Hyaluronan matrix can then be observed and quantified by microscopic image analysis of clear zones around individual cells, from which exogenously added fixed red blood cell particles are excluded.
Keywords: Aggrecan; Hyaluronan; Immunofluorescence; Particle exclusion; Pericellular matrix.