The orthodoxy in biology states that every cell in your body
shares exactly the same DNA. It's your identity, your indelible
fingerprint, and since all the cells in your body have been
duplicated from your initial unique stem cell these zillion of
offspring cells all maintain your singular DNA sequence. It
follows then that when you submit a tissue sample for genetic
analysis it doesn't matter where it comes from. Normally
technicians grab some from the easily accessible pars of your
mouth, but they could just as well take some from your big toe,
or your liver, or eyelash and get the same results. I believe,
but cannot prove, that the DNA in your body (and all bodies)
varies from part to part. I make this prediction based on what
we know about biology, which is that natures abhors uniformity.
No where else in nature do we see identity maintained to such
exactness. No where else is there such fixity. I do not expect
intra-soma variation to diverge very much. Indeed the genetic
variation among individual humans