Radiocarbon dating—also known as carbon-14 dating—is a technique used by archaeologists and historians to determine the age of organic material.
It can theoretically be used to date anything that was alive any time during the last 60,000 years or so, including charcoal from ancient fires, wood used in construction or tools, cloth, bones, seeds, and leather.
First, the older the object, the less carbon-14 there is to measure.
Radiocarbon dating is therefore limited to objects that are younger than 50,000 to 60,000 years or so.
There are eight AMS laboratories currently operating in the Unites States.