Table of Contents
Advertisement
Section 2 Introduction to Particle Delivery
In vertebrates, the epidermal cells of the skin are the most obvious target (Yang et al. 1990, Williams et al.
1991). In vivo experimental systems have targeted the skin for vaccination studies (Tang et al. 1992, Fynan
et al. 1993, Eisenbraun et al. 1993), wound healing studies (Andree et al. 1994), and cytokine gene therapy
studies in mouse tumor models (Sun et al. 1995, Keller et al. 1996, Rakhmilevich et al. 1996). In addition to
skin, muscle and internal organs, including liver, pancreas, spleen, kidney, etc., when appropriately exposed
surgically, can also be targeted in vivo (Yang et al. 1990, William et al. 1991, Cheng et al. 1993). Using the
Accell Gene Gun, both primary and established cultures of mammalian cells have been transfected in
vitro and ex vivo (Albertini et al. 1996, Mahvi et al. 1996, Rakhmilevich et al. 1996). Additionally, transgenic
expression of b-galactosidase, luciferase, IL-12, granulocyte macrophage colony–stimulating factor and a
nuclear papillomavirus protein has been demonstrated following in vivo transformation (Sundaram et al.
1996, Keller et al. 1996, Rakhmilevich et al. 1996). Meristematic tissues and leaves are obvious target cells
for in vivo transformation of plants.
Operating Principle of the Helios Gene Gun System
The Helios Gene Gun System consists of all of the components needed to prepare DNA-coated
microcarriers, coat the DNA-microcarrier suspension onto the inner surface of the GoldCoat Tubing, cut the
tubing into cartridges, which are used in the Helios Gene Gun, and finally propel the microcarriers and their
associated DNA into cells.
Prior to transfection, the plasmid DNA must be attached to the gold particles. This is accomplished by
precipitation of the DNA from solution in the presence of gold microcarriers and the polycation spermidine
by the addition of CaCl
. The particles are then washed extensively with ethanol to remove the water and
2
resuspended in ethanol. Using the Tubing Prep Station, the DNA/microcarrier solution is coated onto the
inner wall of GoldCoat Tubing and dried. The tubing is then cut into 0.5" length cartridges using the Tubing
Cutter. These cartridges, when inserted into the cartridge holder of the Helios Gene Gun, are the source of
the DNA that is propelled into the target cells by the helium discharge.
4 | Helios Gene Gun System
Advertisement
Table of Contents
