Particle-mediated transformation of mammalian unattached cells

A method of genetically transforming mammalian unattached cells comprising the steps of:

• (a) preparing copies of a nucleic acid construct which expresses a gene product in mammalian cells;
• (b) coating copies of the nucleic acid construct onto carrier particles of dense material;
• (c) layering the carrier particles produced in step (b) on a planar carrier sheet;
• (d) placing the carrier sheet onto a spark discharge chamber;
• (e) placing a droplet of water between the end of a pair of spaced electrodes within said spark discharge chamber so as to bridge the gap between the electrodes;
• (f) isolating mammalian unattached cells from a liquid suspension, the unattached mammalian cells selected from the group consisting of lymphocytes and bone marrow cells;
• (g) placing the cells on a porous target surface, selected from the group consisting of filter paper and polycarbonate membrane, wherein the amount of moisture in the target surface is minimal, but sufficient for cell viability;
• (h) initiating a discharge of high voltage electric force between the electrodes so that a spark bridges the gap between the electrodes, vaporizing the water droplet and accelerating the carrier sheet toward the cells, the carrier sheet being restrained from hitting the cells but the carrier particles traveling into the cells, the force with which the carrier particles are accelerated into the cells being adjustable by adjusting the voltage of the high voltage electric force applied to the electrodes so that the nucleic acid construct is introduced into the cells with minimal damage to the cells;
• and
• (i) verifying the existence and expression of the construct in the cells.