Cell adhesion plays an important role in regulating diverse physiological functions of cells,and quantitatively characterizing the adhesive behaviors at single-cell level benefits understanding the biology of cells.The advent of atomic force microscopy(AFM)provides a powerful method for investigating the biophysical properties of biological systems at micro/nanoscale under aqueous conditions,and particularly AFM-based single-cell force spectroscopy(SCFS)is able to measure the adhesion forces of single cells.Nevertheless,current SCFS assays are commonly performed on adherent cells,and SCFS studies on mammalian suspended cells are still scarce.In this work,AFM-based SCFS was utilized to measure the adhesion forces of lymphoma cells.First, the adhesion forces between lymphoma cells and rituximab(an antibody which binds to the CD20antigen on lymphoma cells to activate immunotherapy)were investigated.Then the effects of antibody concentration and experimental parameters on the adhesion force measurements were investigated.Next,the intercellular adhesion forces between lymphoma cells were quantified.The research demonstrates the capabilities of AFM-based SCFS in detecting the adhesive behaviors of mammalian suspended cells and also provides novel insights into the adhesion of lymphoma cells,which will have potential impacts on single-cell biomechanical assays.