For systemic injections via the tail vein, syringes equipped with 27 gauge needles have been used with a gold nanoparticle concentration of optical density (OD) = 100. The viscosity of colloidal gold nanoparticles can vary with size, shape, and surface coatings. This concentration maximizes the balance between acceptably low viscosity for injection and the amount of gold that can be delivered.
In addition to volumes and concentration, the following are practical notes for in vivo injections of gold nanoparticles based on NanoHybrids experience. To account for vein misses or collapse due to the small nature of murine tail veins syringes have been loaded with up to 250 uL of gold nanoparticles at OD = 100.
Disclaimer: These numbers were derived from past experience of injections of gold nanoparticles in the tail vein of mice and serve as a general rule of thumb. In no way are these numbers applicable for all applications, animal species or breeds, nanoparticle types, injection sites, or animal models. Before planning your animal injection, we recommend reaching out to your local IACUC for guidelines and protocols.
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