EZ-SPOTs: a simple, low-cost, high-throughput liquid handling platform applied to antimicrobial susceptibility testing of clinical isolates.

Abstract

High-performance liquid handling is essential for a wide range of experiments. Previously, we introduced the Surface Patterned Omniphobic Tiles (SPOTs) platform, which enables manipulation of hundreds to thousands of independent experiments without costly equipment or excessive consumable expenses. However, the SPOTs platform uses a custom coating that requires a chemical synthesis step. This coating is also easily damaged by handling and requires careful manipulation, making it challenging to transport and interface the platform with existing well plates. To overcome these challenges, here we introduce the EZ-SPOTs platform which can be created in an hour with common fabrication tools and three components: glass, a phobic coating, and plastic. EZ-SPOTs preserve many of the SPOTs platform's strengths including ease of use, the ability to handle a wide range of volumes, and scalability, but by adopting a robust, abrasion-resistant coating, EZ-SPOTs devices can be reused. Additionally, this improved robustness enables the platform to address the "chip-to-lab" obstacle by directly interfacing with 96-well plates. Here, we describe the fabrication of EZ-SPOTs and showcase how devices can be reused to test many isolates for antimicrobial susceptibility. These results quantitatively match current gold-standard assays, and the increased throughput provides substantially more information than standard approaches.