Adding a small volume quickly to many micro-chambers with fluid walls

Overview
Microtiter plates are essentially arrays of miniature test tubes; individual chambers with solid plastic walls typically hold a few micro-liters. Much smaller volumes can be contained in arrays of chambers (GRIDs) with fluid walls (Soitu C et al, 2018, Proc Natl Acad Sci USA 115, E5926-E5933). When an equal volume of a liquid is added to each chamber in a conventional plate, the delivering pipet must be raised/lowered over walls between wells, a pump started/stopped to eject liquid, and the pipet tip discarded/replaced to prevent ‘carry-over’ between wells. With GRIDs, there are no solid walls, and so no need to raise/lower the tip or start/stop a pump. Consequently, one liquid can be delivered to many chambers by one pipet as it moves at constant speed/height, ejecting liquid continuously through the immiscible overlay (which effectively ‘washes’ the tip between chambers). In this YouTube movie (runs in real time), such 'scanning' delivers 70 nL to each of 1,024 chambers in a 6 cm dish in 90 s – without detectable ‘carry-over’.

Nuclear Structure and Function Research Group