Targeted permeabilization of the cell wall and extraction of charged molecules from single cells in intact plant clusters using a focused electric field.

The extraction of cellular contents from plant cells covered with cell walls remains a challenge, as it is physically hindered by the cell wall. We present a new microfluidic approach that leverages an intense pulsed electric field for permeabilizing the cell wall and a focused DC electric field for extracting the cellular contents selectively from a few targeted cells in a cluster of intact plant cells. We coupled the approach with on-chip fluorescence quantification of extracted molecules leveraging isotachophoresis as well as off-chip reverse transcription-quantitative polymerase chain reaction detecting extracted mRNA molecules. Our approach offers a workflow of about 5 min, isolating a cluster of intact plant cells, permeabilizing the cell wall, selectively extracting cytosolic molecules from a few targeted cells in the cluster, and outputting them to off-chip analyses without any enzymatic reactions. We anticipate that this approach will create a new opportunity to explore plant biology through less biased data realized by the rapid extraction of molecules from intact plant clusters.