The process of 'genetic fingerprinting' uses the DNA from certain
regions of particular chromosomes of the subject. These portions show high
variability from individual to individual, but also show family traits - hence
their use in tracking true (!) dependants of immigrants to the UK. The DNA can
be extracted from any cells, although I believe that is is easier from some
than others.  Usually, a mouth swab is used forensically as I think cells from
the lining of the mouth are easy to dislodge, and saliva will contain some
cells anyway.
        As for other body fluids, clearly {*filter*} does contain cells ( {*filter*}) but
sweat wouldn't. I wouldn't expect everyone's sweat to be the same - similar,
but it might need a good analytical technique to see differences; and whether
those differences could nail an individual, I don't know. Clearly, sweat is
different from indvidual to individual, as we all smell different!

Any molecular biologists care to expand?

                Andy

-------------------------------------------------------------------------------
Andrew Oliver                       [ any opinions expressed here are purely
Crosfield Electronics Ltd             arbitrary, and liable to change
Three Cherry Trees Lane               without notice ]
Hemel Hempstead, Herts HP2 7RH,
England.

-------------------------------------------------------------------------------