Locating marker/tracer elements detectable by neutron activated analysis within or on carrier microspheres, including microspheres used in biological experimentation

摘要

Microspheres are permanently marked with non-radioactive stable isotopes of elements suitably detected by neutron activation analysis. The marked microspheres are suitable to permanently label diverse things. For example, families of stable-multiple-isotope-marked microspheres injected into an animal become lodged by the circulating blood within selected tissues of an animal during blood flow analysis experimentation. Absolute and relative abundances of these stable-isotope-marked microspheres residing within harvested tissues are readily accurately automatically measured in situ within the harvested tissue samples by neutron activation analysis. The quantitatively measured abundance of the isotopes, and associated microspheres, are accurately indicative of the former flow of blood containing the microspheres to the tissue. Microspheres are preferably marked with stable isotopes of gold, antimony, lanthanum, samarium, europium, terbium, holmium, ytterbium, lutetium, hafnium, tantalum, tungsten, rhenium, osmium, iridium, scandium and/or bromide.