Electrofusion of single cells in picoliter droplets

Abstract

We present a microfluidic chip that enables electrofusion of cells in microdroplets, with exchange of nuclear components. It is shown, to our knowledge for the first time, electrofusion of two HL60 cells, inside a microdroplet. This is the crucial intermediate step for controlled hybridoma formation where a B cell is electrofused with a myeloma cell. We use a microfluidic device consisting of a microchannel structure in PDMS bonded to a glass substrate through which droplets with two differently stained HL60 cells are transported. An array of six recessed platinum electrode pairs is used for electrofusion. When applying six voltage pulses of 2–3 V, the membrane electrical field is about 1 MV/cm for 1 ms. This results in electrofusion of these cells with a fusion yield of around 5%. The operation with individual cell pairs, the appreciable efficiency and the potential to operate in high-throughput (up to 500 cells sec−1) makes the microdroplet fusion technology a promising platform for cell electrofusion, which has the potential to compete with the conventional methods. Besides, this platform is not restricted to cell fusion but is also applicable to various other cell-based assays such as single cell analysis and differentiation assays.

Application of Microfluidic Technology in Field of Antibody Preparation

“…As an alternative method, a droplet-based microfluidic system can also be created for a high-throughput hybridoma production platform, including cell encapsulation, droplet pairing, droplet fusion and droplet shrinkage, then the cells form intimate contact for subsequent electrical fusion (R. M. Schoeman, Kemna, Wolbers, & van den Berg, 2014), as shown in Figure 4B. The results confirmed that the fusion rate of around 5%, droplet electrofusion was a promising cell fusion platform (Rogier M. Schoeman et al, 2018).…”

Advances in hybridoma preparation using electrofusion technology

“…4B) . The micro channels were also yin-yang-shaped and produced droplets with a volume of 50 pL [26] . The obvious difference from the previous study is that the number of electrodes increased from one to six.…”

Dissecting the stem cell niche with organoid models: an engineering-based approach

“…An advantage of this technique over microwells is the speed of droplet generation and the ease of automation, which allows high-throughput assembly of cell aggregates (Allazetta and Lutolf, 2015;Chan et al, 2013;Tumarkin et al, 2011). In contrast to microwells, which rely on probabilistic cell loading, recent advances in droplet-based microfluidics can achieve singlecell droplet loading and can load droplets with combinations of cell types with a precision that exceeds Poisson limitations (Collins et al, 2015;Edd et al, 2008;Schoeman et al, 2014). These devices can also be used to capture precise cell pairs, facilitating the dynamic dissection of cell-cell interactions from the initiation of contact (Dura et al, 2016).…”