title: Screening of Small Molecule Microarrays for Ligands Targeted to the Extracellular Epitopes of Living Cells.
abstract: The screening of living cells using high-throughput microarrays is technically challenging. Great care must be taken in the chemical presentation of potential ligands and the number of collisions that cells make with them. To overcome these issues, we have developed a glass slide-based microarray system to discover small molecule ligands that preferentially bind to one cell type over another, including when the cells differ by only a single receptor. Chemical spots of 300 ± 10 μm in diameter are conjugated covalently to glass slides using an arraying robot, and novel near-infrared fluorophores with peak emission at 700 nm and 800 nm are used to label two different cell types. By carefully optimizing incubation conditions, including cell density, motion, kinetics, detection, etc. we demonstrate that cell-ligand binding occurs, and that the number of cells bound per chemical spot correlates with ligand affinity and specificity. This screening system lays the foundation for high-throughput discovery of novel ligands to the cell surface.
authors.affiliation: Division of Hematology/Oncology, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02215, USA.
authors.forename: Jeong Heon
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Division of Hematology/Oncology, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02215, USA.
authors.forename: Kai
authors.initials: K
authors.lastname: Bao
authors.affiliation: Division of Hematology/Oncology, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02215, USA ; Curadel, LLC, 377 Plantation Street, Worcester, MA 01605, USA.
authors.forename: John V
authors.initials: JV
authors.lastname: Frangioni
authors.affiliation: Division of Hematology/Oncology, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02215, USA ; Department of Cogno-Mechatronics Engineering, Pusan National University, Busan 609-735, Korea.
authors.forename: Hak Soo
authors.initials: HS
authors.lastname: Choi
keywords: cell-based assay; drug discovery; high-throughput screening; live cells; microarrays; small molecules