Facile approach to observe and quantify the α(IIb)β3 integrin on a single-cell.

We report for the first time seeing and counting integrin a(IIb)beta(3) on a single-cell level. The proposed method is based on the using of the Au cluster probe. With the fluorescent property of Au-24 cluster and the specific targeting ability of peptide, our probe can directly visualize integrin a(IIb)beta(3) on the membrane of human erythroleukemia cells (HEL) via confocal microscopy. On the basis of the accurate formula of our probe (Au(24)Peptide(8)), the number of integrin a(IIb)beta(3) can be precisely counted by quantifying the gold content on a single HEL cell via laser ablation inductively coupled plasma mass spectrometry. Our results reveal that the number of integrin a(IIb)beta(3) on a single cell varies from 5.75 x 10(-17) to 9.11 x 10(-17) mol, because of the heteroexpression levels of a(IIb)beta(3) on individual cells.