Blood typing cannot, in general, *prove* a man to be father (see above).
However, courts *do* have to find a decision; the procedures for
reaching a decision are, of course, specific for a country's legal
system.
In Germany, a probability of 99,8 % suffices for the "legal proof"
of fatherhood. Cases with a probability less than 99,8 % require
additional expert testimonies. While these figures seem to indicate
a bias toward alleged fathers (and against the mothers), this is
not so in reality. It turns out to be very easy to exclude non-fathers
with a chance of 95 % .
For the biostatistics of it, check out the Essen-Moeller formula.
Blood group systems used for testing are
AB0, P, Kell, Duffy, Kidd, Rhesus (a.k.a. CDE);
Serum protein properties used for testing are
Haptoglobin, Gc(group specific components), C3 (complement),
Tf (transferring), Pi (alpha1-antitrypsin), PLG (plasminogen)
Factor XIIIa, Factor XIIIb, Bf (forgot what that is),
AHS (alpha2-HS-glykoprotein).
Cited courtesy of my exam preparation notes.
Christoph
Sorry, no documentation on HAMBURG /HAMBURGERS available.
Christoph Bobrowski, bobrowski at uke.uni-hamburg.de
