A multifunctional pipette

TLDR

Microfluidics enables cellular‑scale manipulation and analysis, but most devices confine processing to closed channels, limiting sample preparation and use. The authors introduce a non‑contact open‑volume microfluidic pipette that overcomes these limitations by providing a multifunctional handling and dispensing tool. Its design optimises geometry for optical microscopy and incorporates integrated reservoirs to minimise reagent use, contamination, and cleaning. Performance tests using epifluorescence and TIRF microscopy showed exchange times of ~200 ms at ~100 nm and ~130 ms at ~30 µm from the surface.

Abstract

Microfluidics has emerged as a powerful laboratory toolbox for biologists, allowing manipulation and analysis of processes at a cellular and sub-cellular level, through utilization of microfabricated features at size-scales relevant to that of a single cell. In the majority of microfluidic devices, sample processing and analysis occur within closed microchannels, imposing restrictions on sample preparation and use. We present an optimized non-contact open-volume microfluidic tool to overcome these and other restrictions, through the use of a hydrodynamically confined microflow pipette, serving as a multifunctional solution handling and dispensing tool. The geometries of the tool have been optimised for use in optical microscopy, with integrated solution reservoirs to reduce reagent use, contamination risks and cleaning requirements. Device performance was characterised using both epifluorescence and total internal reflection fluorescence (TIRF) microscopy, resulting in ∼200 ms and ∼130 ms exchange times at ∼100 nm and ∼30 μm distances to the surface respectively.