Radiocarbon dating a third radiocarbon revolution. Occasionally, radiocarbon dating techniques date an object of popular interest, for example the Shroud of Turin, a piece of linen cloth thought by some to bear an image of Jesus Christ after his crucifixion. Three separate laboratories dated samples of linen from the Shroud in 1988; the results pointed to 14th-century origins, raising doubts about the shroud's authenticity as an alleged 1st-century relic. Researchers have studied other radioactive isotopes created by cosmic rays to determine if they could also be used to assist in dating objects of archaeological interest; such isotopes include , , , ,
Isotopic labeling isotopic tracer. However, the most commonly used stable isotope tracers involve relatively light isotopes, which readily undergo fractionation in natural systems. See also isotopic signature. A radiogenic isotope tracer involves an isotope produced by radioactive decay, which is usually in a ratio with a non-radiogenic isotope (whose abundance in the earth does not vary due to radioactive decay). Stable isotope labeling involves the use of non-radioactive isotopes that can act as a tracers used to model several chemical and biochemical systems. The chosen isotope can act as a label on that compound that can be identified through nuclear magnetic resonance(NMR)