A Technique to Detect Extrapulmonary Tuberculosis via Superparamagnetic Nanoprobes

To inoculate experimental animals with M. bovis BCG, first, reconstitute the lyophilized vaccine, or bacterial stock, in Sauton's medium, and dilute the reconstituted stock solution with saline. Next, load 100 microliters of the solution into one 1-milliliter syringe per animal, and inject the entire volume of bacteria, intradermally, into the left or right dorsal scapular skin of each mouse.

For in vivo magnetic resonance imaging of live nanoprobe injected animals, acquire baseline T2-weighted fast-spin echo images of each anesthetized experimental animal, before injecting two nanomolar of SPIO-Tb antibody probes, suspended in 200 microliters of saline into the tail vein of each mouse. Then, image the animals again, immediately after the injection, and every five minutes for the next 30 minutes.

At the end of the imaging session, quantitatively analyze the magnetic resonance images, using the signal intensity as a measurement of the defined regions of interest in comparable locations of an M. tuberculosis granuloma center, and the back muscle adjacent to a granulomatous area. Then, use the formula to calculate the relative signal enhancements, using the signal intensity measurement before, and, zero to three hours, after the injection of the contrast agents.