ANDeS: An automated nanoliter droplet selection and collection device

Joaquín E Urrutia Gómez; Razan El Khaled El Faraj; Moritz Braun; Pavel A Levkin; Anna A Popova

doi:10.1016/j.slast.2023.11.002

ANDeS: An automated nanoliter droplet selection and collection device

SLAS Technol. 2024 Feb;29(1):100118. doi: 10.1016/j.slast.2023.11.002. Epub 2023 Nov 18.

Authors

Joaquín E Urrutia Gómez¹, Razan El Khaled El Faraj¹, Moritz Braun², Pavel A Levkin³, Anna A Popova⁴

Affiliations

¹ Institute of Biological and Chemical Systems - Functional Molecular Systems (IBCS-FMS), Karlsruhe Institute of Technology, Hermann-von-Helmholtz Pl. 1, Eggenstein-Leopoldshafen 76344, Germany.
² Institute for Applied Materials - Ceramic Materials and Technologies, Karlsruhe Institute of Technology (KIT), Haid-und-Neu straße 7, Karlsruhe 76131, Germany.
³ Institute of Biological and Chemical Systems - Functional Molecular Systems (IBCS-FMS), Karlsruhe Institute of Technology, Hermann-von-Helmholtz Pl. 1, Eggenstein-Leopoldshafen 76344, Germany; Institute of Organic Chemistry, Karlsruhe Institute of Technology, Kaiserstraße 12, Karlsruhe 76131, Germany. Electronic address: pavel.levkin@kit.edu.
⁴ Institute of Biological and Chemical Systems - Functional Molecular Systems (IBCS-FMS), Karlsruhe Institute of Technology, Hermann-von-Helmholtz Pl. 1, Eggenstein-Leopoldshafen 76344, Germany. Electronic address: anna.popova@kit.edu.

PMID: 37981010
DOI: 10.1016/j.slast.2023.11.002

Abstract

The Droplet Microarray (DMA) has emerged as a tool for high-throughput biological and chemical applications by enabling miniaturization and parallelization of experimental processes. Due to its ability to hold hundreds of nanoliter droplets, the DMA enables simple screening and analysis of samples such as cells and biomolecules. However, handling of nanoliter volumes poses a challenge, as manual recovery of nanoliter volumes is not feasible, and traditional laboratory equipment is not suited to work with such low volumes, and small array formats. To tackle this challenge, we developed the Automated Nanoliter Droplet Selection device (ANDeS), a robotic system for automated collection and transfer of nanoliter samples from DMA. ANDeS can automatically collect volumes from 50 to 350 nL from the flat surface of DMA with a movement accuracy of ±30 µm using fused silica capillaries. The system can automatically collect and transfer the droplets from DMA chip into other platforms, such as microtiter plates, conical tubes or another DMA. In addition, to ensure high throughput and multiple droplet collection, the uptake of multiple droplets within a single capillary, separated by air gaps to avoid mixing of the samples within the capillary, was optimized and demonstrated. This study shows the potential of ANDeS in laboratory applications by using it for the collection and transfer of biological samples, contained in nanoliter droplets, for subsequent analysis. The experimental results demonstrate the ability of ANDeS to increase the versatility of the DMA platform by allowing for automated retrieval of nanoliter samples from DMA, which was not possible manually on the level of individual droplets. Therefore, it widens the variety of analytical techniques that can be used for the analysis of content of individual droplets and experiments performed using DMA. Thus, ANDeS opens up opportunities to expand the development of miniaturized assays in such fields as cell screening, omics analysis and combinatorial chemistry.

Keywords: Automation; Droplet microarray; High throughput; Liquid handling; Miniaturization.

MeSH terms

Miniaturization*