Preparation of specimen arrays on an em grid

Abstract

The invention provides systems or apparatuses for dispensing aqueous materials for electron microscopy (EM). The systems allow dispensing of aqueous materials onto an EM sample grid at individual specimen locations in an ordered array of specimen locations, with each individual specimen location in the array of locations. The systems contain a holder for reversibly receiving an EM sample grid, and a dispenser containing one or more dispensing elements that are configured to discretely dispense one or more aqueous solutions from the dispensing elements onto a plurality of individual specimen locations. The dispenser is able to provide an ordered array of discrete specimen locations discontinuous with one another. In the systems, at least one dispensing element is configured to dispense picoliter volumes of one or more of the aqueous solutions. Additionally, the systems contain a drive mechanism to position the EM sample grid relative to the one or more dispensing elements, as well as one or more reservoirs operably linked to the dispenser for holding the one or more aqueous solutions to be discretely dispensed onto each individual specimen location in the array of locations.