MultiDots consist of several quantum dots within a patented PEG polymer coating. The pegylated fluorescent nanoparticles have very tight size distribution and the amine functional groups on the surface allows conjugation of proteins to label cells of interest. MultiDots with a tighter emission spectrum than current fluorescent reagents, reduces spectral overlap, increases assay sensitivity and eliminates complex spectral compensation. The ICRF44 antibody conjugated to this MulitDot reacts with human CD11b,a 165 kDa adhesion molecule also known as integrin αalpha M. CD11b associated with integrin beta2 (CD18) is expressed on the surface of monocytes, granulocytes, activated lymphocytes and a subset of NK cells. CD11b is a receptor for intercellular adhesion molecule family members CD54, CD102 and CD50 as well as for iC3b. These adhesions are crucial in cell-cell and cell-matrix interactions.