in-111 pseudomonas aeruginosa: a simple method of labeling live bacteria with a gamma-emitting radioisotope

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 μci of commercially prepared 111in-oxine resulted in a yield of 0.0004 μci of cell-associated 111in per 106 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 nontoxic, stable gamma-emitting bacterial tracer.