Electrical field-induced fusion to create giant insulin-producing β-cells

Abstract

A technique for electrical field-induced cell fusion was modified to obtain a large amount of giant insulin-producing cells from normal pancreatic β-cells as well as from the clonal cell line RINm5F. The fusion was established by one or several pulses of 1.50-2.75 kV with a time constant of 175-550 μsec. The resulting electrical field strength corresponded to 2.5 - 10⁵ V/m. After fusion the giant cells (diameter ≥20 μm) comprised as much as 60% of the cells excluding trypan blue. Except for being polynucleated, the giant cells displayed similar cytological characteristics as their normal-sized counterparts both with regard to appearance and distribution of insulin-containing secretory granules and other intracellular organelles. The fused RINm5F cells survived under tissue culture conditions, but when cultured for more than one week, division of the giant cells resulted in normal-sized cells.