Altering the biochemical state of individual cultured cells and organelles with ultramicroelectrodes

TLDR

The study presents an efficient technique for selectively manipulating the contents of individual cells and proposes observing dye transfer into organelles at high electric field strengths. The method uses low‑voltage, highly focused electric fields generated by microelectrodes to electroporate polar, cell‑impermeant solutes—including dyes, fluorogenic reagents, DNA, and plasmids—into single cells and organelles. The technique achieves high‑resolution electroporation, enabling selective delivery of fluorescent dyes, calcium indicators, and plasmid DNA into individual hippocampal progenitor cells, their submicrometer processes, and COS‑7 cells, thereby allowing construction of cellular networks with distinct biochemical properties.

Abstract

We describe an efficient technique for the selective chemical and biological manipulation of the contents of individual cells. This technique is based on the electric-field-induced permeabilization (electroporation) in biological membranes using a low-voltage pulse generator and microelectrodes. A spatially highly focused electric field allows introduction of polar cell-impermeant solutes such as fluorescent dyes, fluorogenic reagents, and DNA into single cells. The high spatial resolution of the technique allows for design of, for example, cellular network constructions in which cells in close contact with each other can be made to possess different biochemical, biophysical, and morphological properties. Fluorescein, and fluo-3 (a calcium-sensitive fluorophore), are electroporated into the soma of cultured single progenitor cells derived from adult rat hippocampus. Fluo-3 also is introduced into individual submicrometer diameter processes of thapsigargin-treated progenitor cells, and a plasmid vector cDNA construct (pRAY 1), expressing the green fluorescent protein, is electroporated into cultured single COS 7 cells. At high electric field strengths, observations of dye-transfer into organelles are proposed.