Abstract: An improved method is described for the synthesis of aspartame using a condensation reaction between the alpha-carboxyl group of the L-aspartic acid and the amino group of the methyl L-phenylalaninate catalyzed by an enzyme. The method allowed efficient and cost effective production of aspartame. A method of identifying an enzyme useful for preparing aspartame is also described.

Abstract: An apparatus for forming a surface reservoir to hold a sample for a desirable period of time is described. The apparatus contains a platform, a solid surface disposed onto the platform, and an assembly of a bottomless vessel mounted on the solid surface. Also described is an apparatus that forms an array of surface reservoirs on a solid surface when multiple bottomless vessels are used, which can be used for high throughput applications. The apparatus can be used in applications on a solid surface, such as immunohistochemistry (IHC), oligo synthesis, peptide synthesis, ELISA, DNA array, peptide array, protein array, antibody array, tissue array, cell culturing, etc.