| abstract |
PCT No. PCT/US95/03355 Sec. 371 Date Dec. 18, 1996 Sec. 102(e) Date Dec. 18, 1996 PCT Filed Mar. 23, 1995 PCT Pub. No. WO95/25737 PCT Pub. Date Sep. 28, 1995A method to determine the molecular weights of femtomole or smaller quantities of small molecules, such as peptides, oligonucleotides, or heterocyclics, covalently attached to polystyrene beads on a grid, is presented using imaging time-of-flight secondary ion mass spectrometry (TOF-SIMS). The determination is made possible by selectively clipping the bond linking the small molecule to the bead, followed directly by a TOF-SIMS assay of the bead on the grid. The method can be applied to large numbers of polystyrene beads having different small molecules attached thereto for direct characterization of massive combinatorial libraries. |