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 CMSSB antibody conjugated to MultiDot specifically reacts with human CD56, or Neural Cell Adhesion molecule (NCAM). CD56 is a 140 kDa transmembrane glycoprotein also known as Leu-19 or NKH1. It is expressed on NK and NKT cells and has a role in cellular adhesion.