In-111 Pseudomonas aeruginosa: A simple method of labeling live bacteria with a gamma-emitting radioisotope

Abstract

We describe a simple and reliable technique for labeling Pseudomonas aeruginosa with a readily available commercial preparation of indium-111 (111In) oxine. Labeling of a heavy bacterial suspension with 500 mu Ci of commercially prepared 111In-oxine resulted in a yield of 0.0004 mu Ci of cell-associated 111In per 10(6) colony-forming units (CFU). The label was 88% bacterially associated and did not effect viability of the organism. Radiolabeling a gram-negative organism with 111In-oxine provides a non-toxic, stable gamma-emitting bacterial tracer.

Imaging Stem Cell Implant for Cellular-Based Therapies

“…Direct labeling is to introduce a marker into or onto the cells before transplant/implant that is stably incorporated or attached to the cells. Examples include labeling with iron oxide particles such as the super paramagnetic iron oxides (SPIO) or perfluoropolyether or perfluorocarbon nano-beacons for Magnetic Resonance (MR) imaging (13)(14)(15) (18)(19)(20), which is adapted from traditional labeling of blood cells such as leukocytes for use in infection/ inflammation imaging in Nuclear Medicine (21)(22)(23). Direct labeling for MR imaging allows the depiction of initial deposition of the implanted stem cells, but the imaging signal diminishes or becomes undetectable with cell division.…”