Jonathan Wingfield, AstraZeneca, Cambridge, UK

At SLAS 2015 (Washington) we received the Innovation Award for our work describing the early development of an acoustic loading system for a mass spectrometer to create a novel label-free detection platform for lead discovery and other laboratory applications. The novel acoustic source is capable of generating a mist of droplets in the 50-100fL range, with the droplets being ionized as they pass through a charged field and fired directly into the mass detector. This direct injection approach enables a sampling rate of 3 wells per second (10,000 samples per hour), fast enough to support high throughput screening (HTS). For biochemical targets this offers the ability to perform hit discovery assays with the direct measurement of substrate to product conversion.

Over the last year we have made significant progress towards demonstrating the utility of our system as a biochemical HTS platform. To deliver the speed required to meet the demands of HTS the traditional chromatography (LC) step has been removed. High levels of salt cause a problem for electrospray ionization (ESI) systems as it can steal charge from the analyte and thus suppress the assay signal. This has required that we modify our assay conditions to reduce salt concentration.
For applications which are unable to tolerate low salt conditions we are looking to build an alternative ionization system that would complement ESI and would be useful for metabolomics applications.
We have recently started out first high throughput screen, we will share data on how the acoustic MS end point assay was built and data from the first 50k subset of compounds. The data demonstrates the robustness of the assay and potential cost savings of a high throughput mass spectrometry assay.