Printing chemical libraries on microarrays for fluid phase nanoliter reactions

doi:10.1073/pnas.1530261100

Printing chemical libraries on microarrays for fluid phase nanoliter reactions

Dhaval N. Gosalia*,† and
Scott L. Diamond*,†,‡,§

^*Institute for Medicine and Engineering, Departments of ^†Bioengineering and ^‡Chemical and Biomolecular Engineering, University of Pennsylvania, 1024 Vagelos Research Laboratory, 3340 Smith Walk, Philadelphia, PA 19104

Edited by Peter G. Schultz, The Scripps Research Institute, La Jolla, CA, and approved May 23, 2003 (received for review January 15, 2003)

Abstract

Chemical compounds within individual nanoliter droplets of glycerol were microarrayed onto glass slides at 400 spots/cm². Using aerosol deposition, subsequent reagents and water were metered into each reaction center to rapidly assemble diverse multicomponent reactions without crosscontamination or the need for surface linkage. This proteomics technique allowed the kinetic profiling of protease mixtures, protease–substrate interactions, and high-throughput screening reactions. An inhibitor of caspases 2, 4, and 6 was identified by using a 352-compound combinatorial library microarrayed in quadruplicates on 100 slides and screened against caspases 2, 4, and 6, as well as thrombin and chymotrypsin. From one printing run that consumes <1 nanomole of each compound, large combinatorial libraries can be subjected to numerous separation-free homogeneous assays at volumes 10³–10⁴ smaller than current high-throughput methods.

Footnotes

↵ § To whom correspondence should be addressed. E-mail: sld{at}seas.upenn.edu.
This paper was submitted directly (Track II) to the PNAS office.
Abbreviations: R110, rhodamine 110; AMC, 7-amino-4-methylcoumarin; TRITC, tetramethylrhodamine-5-isothiocyanate; MCA, methylcoumarin-7-amide; boc-VPR-MCA, t-butyloxycarbonyl-valine-proline-arginine-MCA.