In an article by Dennis Vaccaro, Chris Reinchardt, and Ernest Groman on Medical Device Link, a new and novel approach to studying physiological processes is discussed. This new emerging technique called Neutron Interrogation Technology (NIT) “introduces the use of a neutron beam to detect specifically labeled probes designed for therapeutic cell tracking as an illustration of the power of this new detection technology as an in vitro diagnostic.” One outstanding feature of the NIT is that it can be combined with different diagnostic imaging technologies to portray unique physiological information.
NIT mainly developed as an attempt to provide a solution for the problem of quantifying labeled materials in biological samples. “The Principle application of NIT involves studying probes that have been administered to subjects in vivo and are then measured in isolated samples such as blood, organs, and other tissues.”
NIT has a number of properties that afford the life scientist great flexibility in planning and performing diagnostic assays.
First, unlike light photons, neutrons have no charge and are not readily attenuated within the sample. Therefore, NIT is matrix independent; measurements can be made in blood, lymph, brain, or even bone samples without the need for extraction prior to assay.
NIT can be used for multiple parallel assays. The NIT instrumentation developed for counting high-energy photons was designed to have the ability to read across a broad spectrum of photon energies. At least 14 different labels can be measured simultaneously in a single sample.
Prior to neutron irradiation, NIT is a nonradioactive tracking technology; the metallic probes are stable isotopes. Therefore, during the in vivo phase of the testing process, the laboratory scientist does not have to deal with issues of radiation safety or radioactive waste.
The shelf life of a stable-isotope labeled probe is potentially much longer than that of a radioactive label. Isotope half-life and radiolysis often limit the usefulness of any radioactively labeled material. By the time such material is employed, it may have a much lower specific activity and purity than it had when originally produced. Likewise with fluorescently labeled materials: issues involving quenching of the label, along with endogenous fluorescence, can limit the usefulness of any particular preparation.
NIT is a very robust technology in terms of sample handling. Once samples are taken, they can be stored indefinitely at room temperature and in the presence of ambient light. Because only a small portion of the label becomes radioactive during the NIT process, samples can be archived for years and then reactivated with neutrons at a later date in order to be remeasured. This is especially important for preclinical trials, when questions could arise during data analysis…
For more on methodology and advantages of NIT, read the article…