Abstract: A process for automating the setting of parameters for a micro jetting system for dispensing reagents and a jetting system and control system arranged to perform the process of the resent invention are disclosed. The parameters which are adjusted by the system, are voltage level and pulse duration. Typically, the process works by cycling through a plurality of combinations of the two parameters, imaging droplets produced by each of those parameters and analysing those images to detect whether a droplet is formed, and if so, whether that droplet is suitable. In a particularly preferred approach, a statistical approach is used to generate a range of appropriate parameter combinations and an associated likelihood of each of those parameter combinations being acceptable.

Abstract: An array (100) of macromolecules (the primary array), typically proteins is generated by 2D electrophoresis, for example, and subsequently transferred to a support membrane (102) by electroblotting or the like. An image of the primary array is captured (202) and the coordinates of the various macromolecular spots in the primary array are determined (402). The next step of the process is to print a secondary (or micro) array of one or more reagents or chemicals onto one or more spots/coordinates of the primary array with a pico-litre (pl) dispenser (702). If the macromolecules are proteins, the reagents may be enzymes such as Trypsin or GluC. Use of two different enzymes deposited onto different coordinates on the same spot will cleave the protein at different amino acid sites and, when the spot is analysed in a MALDI-TOP mass spectrometer, will provide increased coverage or matching of peptides in the protein.