We present a kinetic model describing adhesion of cells to a supported lipid bilayer due to formation of bonds between cellular receptors and ligands (e.g., peptides or proteins) attached to the bilayer. The model implies a power-law dependence of the adhesion rate on the ligand concentration and takes into account ligand diffusion and association with already adhered cells. For a time interval longer than the sedimentation time, it predicts a sigmoidal dependence of the population of adhered cells on the initial ligand concentration. This feature becomes less pronounced with increasing rate of ligand association with adhered cells. The results obtained are used to interpret recent experiments with rat adult neural progenitor cells. (C) 2007 Elsevier B.V. All rights reserved.