[chris (OP)]

I was asked by someone on the radio today how he might obtain an accurate age for his grandmother? The family are not sure when her exact birthday is, but they think she's nearly 100.

Could they carbon date her, or similar, to find out?!

Chris

[omid]

omid guess this happened exactly to omid's friend's father
and omid guess that they had some x-ray of his right or left (not sure []) to find his real age.

[RD]

Measure the length of her telomeres ... http://en.wikipedia.org/wiki/Telomeres#Systemic_telomere_length_and_aging

Or measure the amount of mutation in her DNA (and that of her mitochondria) ... http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2816353/ 

[Bored chemist]

The best radiocarbon dating can do is tell you when something died and that's clearly not helpful here.
You could ask her what the earliest thing she remembers is and how old she was at the time.
If, for example, she remembers talking to her friends at work about the Titanic's sinking then she is over 100.

[chris (OP)]

Actually, Bruce Buchholz and his colleagues used 14C integration into adipose DNA to age fat cells to work out the lifespan of the average adipocyte (12 years).

http://www.nature.com/nature/journal/v453/n7196/full/nature06902.html

Perhaps the same approach could be used with a life-long post-mitotic (non-dividing) cell, like a neurone, to age an individual?

Chris

[RD]

The ideal candidate ...
http://news.sky.com/skynews/Home/World-News/Georgia-A-Woman-Claims-To-Be-Oldest-Person-In-The-World-At-The-Age-Of-130